Dyes and dyeing

by Charles Ernest Pellew

DIRECT APPLICATION OF COLORS

History.—During the last few years a great deal of attention has been paid to the manufacture and use of stencils for decorating textiles, not only by craft workers of different kinds, but also by art teachers in private and public schools.

The art is not a modern one, even in this country, for I have seen and worked with a series of very interesting stencils cut in brass, which were owned in Philadelphia by the famous old physician, Dr. Benjamin Rush, over a hundred years ago, and were used in his family for marking linen, as well as for decorating homespuns and paper.

The real home of the art, however, is Japan, where, for over three hundred years, stencils have been in common use, largely replacing the wood blocks used in other countries, for decorating the common cotton goods, towels, head coverings, and the like of the lower classes, and also for ornamenting, where embroidery was not desired, the beautiful silks and satins of the wealthy.

Ever since Japan has been opened to the world travelers have been telling wonderful stories of the great skill of the natives in this beautiful art. According to some writers, as soon as a child is born it is given a nickname, and with it, as a sort of totem, a design—a flower, for instance, for a girl—a tree or an animal for a boy—and the like. This design, worked out carefully, after due criticism from all the family elders, is drawn on brown paper and then carefully cut out with a sharp knife by some member or friend of the family. And this stencil is then sent to the local dyer to be used in dyeing the infant’s clothes. This same design, or a modification of it, is attached to the person through life, as his or her own private pattern, and whenever new clothes are needed they are dyed after this same pattern.

Japanese Stencils.—Paper.—It is a common fact that the very first thing noticeable about Japanese stencils, whether brought from some dyehouse in the interior, or whether made more or less mechanically, for the American market, to be sold to students or craftsmen, is the quality of the paper. It is thin, hardly heavier than ordinary writing paper, but exceedingly tough and strong, and cuts very easily, without tearing. It can occasionally be obtained from importers in sheets, and even better qualities can be secured, from among a mass of old stencils, by finding some which have been only partially cut or used up, and carefully cutting out from them the unused portions where these are large enough for the purpose.

FIG. 13—JAPANESE STENCIL KNIFE

FIG. 14—JAPANESE STENCIL BRUSHES

Knives.—In cutting stencil designs our American practice is to use a sharp penknife, or a Sloyd knife, or, as happens occasionally with some of my friends with amiable professional husbands, a surgeon’s scalpel. None of these, however, compare for neatness, accuracy, and ease and comfort of manipulation, with the very simple but extremely effective little Japanese knives shown in Fig. [13]. The knife blade, of very highly tempered steel, is two or three inches long and fits between two flattened plates of wood, tied together tightly at the bottom but springing apart a little toward the top, as a handle. This little spring of the handle is most satisfactory. And as the blade, which is triangular and sharply pointed, is worn away gradually by the constant grinding and sharpening it must receive, the steel can be pushed forward from between the two halves of the handle, until the proper length is reached.

Cutting.—The Japanese draw their designs on paper with India ink, and then, with incredible swiftness and accuracy, the lines are cut, by pushing the knife blade, held with the back downwards, away from the workman, and through the paper which is placed flat on a piece of wood or small tray, with depressions in it half an inch or so deep, to avoid the danger and bother of running the knife point into the wood.

American Practice.—Our way differs somewhat. The design is usually drawn on a separate piece of white paper, and filled in—in black—with India ink. This is then placed underneath the stencil paper which, especially if it has been oiled or paraffined, is translucent enough to show the pattern through, so that the outline can be drawn with a sharp pencil. The outline can also be made by tracing the design down on the stencil paper with the help of a piece of carbon copying paper. This is laid between the design and the stencil paper and then the outline of the design is carefully traced with a sharp-pointed pencil. From these outlines it is easy, with a sharp stencil knife, to cut out the design, although it is customary with us to cut toward the body with the point of the knife down, upon a piece of blotting paper or soft wood so as not to dull it too rapidly.

Ties and Stops.—When stencilling is taught in America great pains are taken to show how the pattern must be planned and cut out, so as to have plenty of “ties” or “stops” in the right places, so as to hold the stencil together. For instance, in making a stencil of a large capital O, the student should be warned that, if the paper was cut all the way around, it would leave a big hole; for the central piece, which would form the centre of the finished letter, would drop out, and could not be kept in place. Accordingly, the stencil would have to be cut carefully, leaving at least two “bridges” or little “tie pieces” of paper, one probably at the top, and the other at the bottom of the O, these being the narrowest points, which would hold the centre in place, and thus complete the figure. Indeed, if these little “steps” or “bridges” of paper should be left out, or become torn or broken, the stencil would be useless. But a situation like this has little or no terror for the Japanese, at any rate when working for their home trade. Their stencils cut for the American market while always interesting, and often charming, are cut, as ours are, from one piece of paper, with stops in the exposed places. But the stencils that have been used, or cut for use, over there, show a very different state of affairs. All of the large, handsome ones, and a large proportion of the smaller, less artistic, and less valuable ones are made, with almost inconceivable skill and patience, in duplicate. And the two parts are afterwards pasted together with absolute accuracy, but with a layer of fine hair, supposedly human hair, between them. These hairs, laid irregularly but evenly, make a sort of network which ties together all portions of the stencil, no matter how disconnected with the rest, or, as we would say, “in the air,” it might be.

So, too, they are in the habit of sewing in, with the finest of hair or of single threads of fine silk, loose pieces or broken pieces, and thus holding them in shape.

It is interesting to study some of them closely and see how neatly this tying is done and how little the time of these unknown workmen must be valued at. For apart from the large picture stencils which, of course, would be worth taking a great deal of pains with, some of the simplest and most ordinary of their native stencils are not only cut but tied in, with extraordinary skill. One of these, valued here at but a few cents, consisted of a background of small figures in shape and size very much like a capital O of the type of this page. The stencil measures some eighteen by ten inches, and there must be between fifteen hundred and two thousand of these O figures on it. Some few of these are now imperfect, but with the exception of a dozen or two, every single one of all these has had the centre cut out, and then sewed into place again, from the sides, so as to be in the exact centre, without a single “stop” or “tie” on the whole paper.

Brushes.—With stencils so very delicately made, it is evident that our crude American style of rubbing in the color, with heavy hands and stiff bristle brushes, would not be much of a success! About one good rub with a brush like that, and every hair in sight would be torn and broken, and what was a minute before a work of art would be a torn mass of brown paper.

Whether any of our American craftsmen have light enough hands to use, successfully, a fine Japanese stencil is doubtful. Personally, I could no more stencil six inches with any of them without ruining it or making a mess of the cloth than I could in a year cut, without tearing, six square inches of any one of a score of cheap and ordinary Japanese stencils which I own, either presented to me or sold at a very low price, as being really too insignificant in value to amount to anything.

But at any rate, the Japanese do not use a stiff bristle brush. Their brushes, in general, are of two sorts, as shown in Fig. [14]. One is a sort of pad, often quite large, five or six inches in diameter, made of rabbit’s fur, tightly bound together with cord or wire, and with a bundle of small sticks spreading out to enclose the pad, and drawn together and tied above, at the upper end, in a sort of pyramid.

FIG. 15—JAPANESE STENCIL, SHOWING HOLES PUNCHED BY HAND TOOL

FIG. 16—JAPANESE STENCIL, EXACT SIZE, SHOWING USE OF STOPS

FIG. 17—JAPANESE STENCIL, EXACT SIZE, SHOWING USE OF SEWING INSTEAD OF STOPS

The other variety is a true brush, of a more ordinary shape, like a flat paint brush, but also made of the very softest and finest, most velvety hairs imaginable, laid extremely close together, and compressed tightly between the two halves of the handle. These can be obtained occasionally from the dealers at reasonable prices, and are delightful to work with. Only, being meant for the soft, light touches of their native workmen, they do not last long when rubbed down on the cloth as is our practise. Their life is considerably increased by pouring some molten beeswax into the back of both goods and brushes with a batik pot, or Tjanting, which prevents the fine hairs from pulling out until the brush is all worn to pieces.

The Care of Stencils.—A word may here be said about taking care of stencils, after they have been cut or purchased. They should always be used on one side, and carefully wiped off with a damp cloth, directly after using. They should always be kept flat, never folded. And, when using them, it must always be remembered that the ties or bridges are the weak spots, and that breaking or tearing them, as a rule, will spoil the stencil. It is, of course, possible to mend them by sewing, or sometimes by patching with tape. But this is always troublesome, and with well paraffined stencils is rarely satisfactory.

The Different Methods of Using Stencils.—In this country, so far as can be ascertained, the common way in which stencils have been used is by brushing through them, on to the cloth, oil paints thinned with turpentine or gasoline. As previously explained, in the chapter on feather dyeing, this is not very satisfactory. For when paint is sufficiently thick to adhere well to the cloth, it is apt to look stiff and shiny. And when it is applied so thin that the structure of the cloth shows through, it is, as a rule, not fast to washing or even to rubbing. Various varnishes are on the market which help considerably to make the paint fast, but even then the results are not nearly so durable as when the proper dyestuffs are used.

The Japanese practice is exclusively with dyes, and they have worked out processes which are perfectly satisfactory, so that their simple, cheap, stencilled towels can stand washing indefinitely without loss of color. And by the use of modern dyestuffs there is no insuperable obstacle to our doing just as well as they.

The use of stencils gives an excellent opportunity to illustrate the three general methods of coloring fabrics, which, as mentioned in the last chapter, consist of:

Direct application of color.
Resist, and
Discharge.

The last two of these will be reserved for the next chapter.

FIG. 18—JAPANESE STENCILS, EXACT SIZE, SHOWING USE OF BOTH STOPS AND NET

Direct Application of Color.—In this intricate work it will generally be found almost a necessity to apply colors through a stencil in the form of a paste, for when the coloring liquid is thin it is very apt to run under the edges of the paper and spoil the design. It is best to thicken it with a little “gum dragon,” a carefully prepared paste of gum tragacanth, to which the coloring matter, and any reagents that are needed, can be added. The nature of the reagents and the class of dyestuffs used depends, of course, upon the kind of material to be stencilled.

(a) Leather.—While not very often used, students interested in leather work will find a carefully designed and neatly cut stencil a most useful medium for obtaining interesting and beautiful effects. The leather, whether bark- or alum-tanned, should be carefully dampened, and then stencilled with a paste containing Basic colors dissolved with a drop of acetic acid. On drying, the leather should be finished as usual. The Acid colors are not nearly so satisfactory for stencilling, although, as already mentioned, they are often advantageous for dyeing, rather than staining, leather fast colors.

(b) Silk.—Silk may easily be stencilled provided the pattern is not expected to be fast to washing.

1.Acid Colors.—These dyes, mixed with a few drops of formic or acetic acid, will color it well, but to make the dyestuff penetrate it is advisable to steam the goods. This can be done with a teakettle provided with a wing tip for the spout, made of tin, or by heating a flatiron or iron plate very hot, and pressing the stencilled goods back down against it, with a damp cloth in between. The hot steam thus produced, passing through the goods, melts the paste and drives the color down into the fibres and sets it there, so that, later, the stencilled goods will stand light rinsing in lukewarm soap and water without running.

2.Salt Colors.—Faster results can be obtained, on silk, with a paste containing salt dyes, with a drop or two of acetic acid, provided the silk is thoroughly steamed afterwards.

3.Basic Colors.—Basic dyes may be used on silk as on wool, leather, or any other animal fibres for direct application, the dyestuff dissolved with a drop of acetic acid, being added to the paste, and then brushed in and, preferably, lightly steamed to sink the paste down into the fibres. These dyes, however, with but few exceptions, are not fast to light, and applied in this way are not fast, either, to washing. By adding some reagents to the paste, however, a Basic stencil paste can be formed which gives colors on silk which will stand active scrubbing excellently.

The Basic Stencil Paste is prepared by mixing with the paste a solution containing the Basic color, dissolved in acetic acid, and also containing a considerable quantity of tannic acid. As long as there is free acetic acid present in this mixture the color remains in solution, but directly the acid is driven off, an insoluble compound remains, formed by the combination of the tannic acid with the color base. This happens on steaming, and the insolubility of the product is still further increased by passing it through a weak bath or wetting it with a weak solution (half a teaspoonful to the quart) of tartar emetic.

Accordingly, to use this stencil paste on silk or, indeed, on cotton, the slightly dampened goods are stencilled with the paste, thinned if desired with water and a little acetic acid. Then directly they are dry enough so as not to run they are well steamed, then the gum rinsed off with a little warm water, and the goods moistened with the tartar emetic. After this they can be washed with soap with little or no danger of running.

(c) Wool.—Wool is rarely stencilled, although stencil patterns can be produced very well on it by using acid colors with a little oxalate of ammonia (about the same amount as the dyestuff), dissolved in a drop or two of water, and thickened with a little gum tragacanth. When this paste is applied with a brush, and then dried, the result is not fast at all, merely a distinct stain; but if steamed at once the oxalate of ammonia decomposes, leaving oxalic acid, which, combining with the color and melting down with it in the fibres, makes the dyestuff adhere quite firmly.

(d) Cotton and Linen.—It is much more difficult to stencil satisfactorily on vegetable goods, such as cotton and linen, than on the animal fibres above mentioned, because they are expected to stand very much more severe treatment. The fastness to washing needed for a handsome silk scarf is far less than for a cotton shirtwaist, or linen table-cover, and unless the results on the latter are at least as fast as the average calico print, the result is considered a failure.

There are three classes of dyes which can be used in this connection, the Basic dyes, the Sulphur dyes, and the Indigo or Vat dyes. The Basic stencil pastes have just been described, in connection with silk stencilling, and when carefully used they will give very fair results on cotton, and even on linen, provided it is free from dressing, and is not too coarse and thick. It is hardly worth while trying to fasten Basic dyes, by hand stencilling, upon such materials as heavy, coarse Russian crash, for instance, such as friends and students have frequently brought in to experiment with. But for light, thin materials, and especially for mercerized goods, poplins and the like, it is possible, with a little practice, to get effects that are fast to ordinary washing.

On the other hand, this method of stencilling has certain disadvantages. It is rather complicated, needing the use of a fixing bath of tartar emetic, a very active poison, by the way, although more uncomfortable than actually dangerous when taken by mistake in one dose, because of the severe vomiting it produces almost immediately. And then, too, the results at best are not really fast to light, and in the case of light pinks and yellows are distinctly fugitive.

Vat Color Stencil Pastes.—Many experiments have been made in our laboratory to work out a satisfactory stencil paste, so that Indigo and other Vat dyes could be applied, simply and easily, with no more difficulty than the usual one of brushing the paste in carefully, and then steaming as soon as possible. In these stencil pastes the Indigo and the other Vat dyes are reduced with the aid of caustic alkali and hydrosulphite before being mixed with the paste, and some special precautions are taken to prevent, as far as possible, the oxidation of the dyestuff before it gets well into the fibre. But, as the ordinary hydrosulphite is apt to decompose on standing, especially when it is wet, it is always best, just before using, to mix well with the paste a little fresh reducing agent, dissolved in a drop of hot water. The reducing agent that should be used for this purpose is not the ordinary hydrosulphite of soda, used for vat dyeing, but a compound of sodium hydrosulphite, “Stencil Salt,” which has the property of keeping better than the other, and also of not acting as a reducing agent until it is heated. This, then, is stirred into the Vat color stencil paste, just before using, and then, when the goods are steamed, the heat and moisture combined will enable it to reduce the color, which will be carried into the fibres in a reduced and dissolved condition. After steaming well for five minutes the color should be developed by a bath in hot soapsuds, after which the goods should be rinsed and dried. With care this process will give very satisfactory results, perfectly fast to both light and washing, after the first loose color has been washed off.

The indigo stencil paste, as prepared, will keep well reduced for quite a long time, and it is frequently quite unnecessary to add any fresh reducing agent to it. If, when taken from the tube or bottle, it looks yellow or yellowish green, it can be applied at once to the cloth, and, if steamed just as soon as possible, it will generally penetrate quite satisfactorily. With the other colors of the series, however, it is hard to tell by the color whether they are reduced or not, and hence the fresh reducing agent, Stencil Salt, should always be added to them. The cloth for stencilling with these pastes, as with the Basic pastes, should not be too thick or heavy, and must be washed quite free from dressing, or the result will not be satisfactory. It should also be slightly dampened, if only by holding over boiling water for a moment or two, so as to help the color to penetrate.

Sulphur Stencil Paste.—We have also found very satisfactory results from pastes made with one of the Sulphur colors, dissolved in a little sodium sulphide and sodium carbonate, and stiffened with a little gum. The presence of a reducing agent helps to keep the color reduced; and, when quickly applied and rapidly steamed, the colors will sink into the fibre and adhere firmly.

The chief drawback with these pastes is the lack of a good red.

Black Stencil Paste.—So far as can be learned, the Japanese use for their stencilling an Indigo paste made on the same general principles as the one just described. Besides this, which is a very favorite color of theirs, they use a red and also a very full black dye, both of which are fast to washing and to light.

What the composition of these last pastes may be it is hard to tell. In our laboratory we have made careful experiments on the subject of stencilling black, and have worked out a method that we consider satisfactory by the use of a modification of the well-known Aniline Black process.

FIG. 19—LARGE AND HANDSOME JAPANESE STENCIL, SHOWING USE OF NET

Aniline Black.—It was noticed, early in the history of dyestuffs, that if aniline was mixed with strong oxidizing agents, and carefully heated, it would undergo a series of color changes resulting, finally, in black. This color, so-called “Aniline Black,” was at one time manufactured and used for a black pigment; but it was soon recognized that its real value would only be developed when it could be formed, in the fibre itself, by the oxidation of aniline or some compound of aniline upon the fibres. After many years of experimenting this problem was solved, and for fifteen or twenty years the blacks most used on cotton and linen by the calico printers, as well as by the dyers, have been one or another of the forms of Aniline Black.

The principle on which these processes are based is as follows: The aniline, usually in the form of aniline salt (aniline hydrochloride), is mixed with an oxidizing agent like chlorate of soda, and also with a small amount of a third substance which, on steaming, acts as a carrier of oxygen between the aniline and the chlorate. This substance, often called a catalytic agent, because at the end of the operation it remains unchanged, although it has accomplished a large amount of work, may be one of a number of compounds as, for instance, a salt of the metal vanadium, prussiate of potash, a salt of copper, etc., each one having special advantages and disadvantages of its own.

Now, almost any printing paste properly composed so as to give a good clear Aniline Black on steaming, (the formulæ can be obtained from any good book on calico printing, or from any competent dyeing chemist), will generally work fairly well as a stencil paste—as long as it is fresh. But even when kept from the air as far as possible, in a tight tube, it decomposes on standing and becomes very unsatisfactory. Besides this, there is always a difficulty with these regular pastes on account of the irregular and uncertain steaming process that can be used by the average craftsman. In a calico print works, the temperature of the steam chest, the proportion of steam in it, and the length of passage of the cloth through it, are all accurately determined, and kept at the exact points necessary for the best results with any given formula. But with irregular steaming, unless very great care is taken with the formula, there is always a danger of “tendering” and burning the fibre, if too much oxidizing agent is present, or of not developing a full black, but a dark green color, if the oxidizing agent is not active enough.

We have, after a great deal of experimenting, worked out a formula which, with reasonable care in steaming, will give a good full black, absolutely fast to light and washing, upon cotton, linen, and silk, without any tendering of the cloth. And, by dividing up the component parts into two separate pastes, which are kept in separate tubes or bottles, and are mixed together only when about to be used, we have gone far to solve the important problem of keeping.

The use of this Black stencil paste is very simple. It comes in two tubes or bottles marked A and B.

When the cloth, free from dressing and slightly dampened, is all ready, equal amounts are taken from each of the two tubes, and mixed together in a watch-glass or small glass or porcelain dish with, if necessary, a drop of water to soften them if they have dried up at all. This mixed paste is then brushed on to, and into, the cloth, and, as soon as dry, is steamed as before described. The black color will develop almost immediately, and, after a few minutes’ steaming, will be found fast to hard washing as well as to light.

Chapter XVI
RESIST AND DISCHARGE STENCILLING

Travelers in Japan inform us that, with their customary ingenuity, the natives there have developed the use of stencils to a point which quite matches the best achievements of our modern calico printers, even though backed by good dyeing chemists. When a young lady there wishes a new dress, she will draw, perhaps with the help of her best young man, and certainly with the advice and criticism of her family, her favorite design on a piece of brown paper, cut it out in stencil form, and send it to the local dyer, with the proper amount of calico or silk or what not, to be properly applied.

Now, in most cases the dyer is instructed to put the pattern on the cloth in colors, blue, black, red, yellow, or mixed shades, and this he does, much as my readers were taught to do in the last chapter, by painting on a stencil paste, to be fixed later by steaming.

The Japanese dyer, by the way, has a great advantage over the American craftsman in his steaming apparatus. No matter how small his place, or how poor his equipment, he always is provided with a neat and satisfactory steam chest, consisting of a copper pot set in a brick or stone fireplace, to hold the boiling water, and above it, a close-fitting box with sides made of lacquered paper, double jacketed to avoid condensation in cold weather, which can be kept full of dry steam for hours at a time, and in which the stencilled goods can be steamed thoroughly and well without fear of spoiling them.

Sometimes, however, the color is to be applied in another way; the cloth itself is to be colored blue or red or black, and the pattern is to be light, either pure white or some light color on a dark background.

The Japanese dyer, from time immemorial, has known how to do this properly, by means of a “Resist.” He prepares a resist paste which he carefully applies to the cloth through the stencil. This is allowed to dry, the cloth is then dyed, and, after the color is properly fixed, it is all thoroughly scrubbed, and the paste, washing off, leaves the cloth, underneath, in its original color.

Resist Stencil Paste.—This process of resist, ancient as it is, is used in Japan to this day, and many, indeed most, of the stencilled towels and piece goods that come from there are done in this way. It has the advantages, especially for the craftsman, over the Direct Color process, in that the color, being applied in a dye-bath, can be fixed readily and uniformly, without the bother and uncertainty of a steaming process. Through a friend, a well-known dyeing chemist, who has travelled in Japan, I learned the composition of the Japanese Resist Paste. They mix rice flour, wheat bran, and a little quicklime (the calcium oxide of the chemist) with water and boil it to make a paste. This they strain, and then they stir in some powdered carbonate of lime (powdered chalk), which thickens and gives some body to the mixture. The paste thus formed is applied, as a rule, not with a brush but with a flat wooden instrument or spatula, with which the paste is laid on as with a trowel, and further, to get the dead white effects so commonly noticed, the paste is put on the back of the cloth as well as on the front.

My friend also explained to me how the Japanese were able to get irregular shaded effects with their stencil work, and at the same time to furnish such beautiful and intricate hand-made work, at such absurdly low prices. These goods are made of very thin porous materials, and the dyer applies with his trowel the thick resist paste, through the stencil, to one piece after another, laying each one, as fast as it is stencilled, carefully on top of the previous one, until a pile has been formed of ten or more separate pieces. This pile is pressed very tightly together, and then the dyestuff, as, for instance, Indigo in solution and thoroughly reduced, is poured on to this mass of goods, soaking through from one to the other, but always kept out of the white parts by the double coating of thick paste.

After a few minutes these pieces are carefully taken off, one by one, exposed to the air until oxidized, and then thoroughly washed until the paste and loose color have all disappeared. For an example of Japanese resist stencil work, dyed in an iron spring, see Plate [III].

PLATE V. JAPANESE TOWELLING DYED BY IMMERSION IN IRON SPRING. THE WHITE PATTERN IS CAUSED BY RESIST STENCILLING

Resist Stencilling with Sulphur Dyes.—Without lavishly copying the Japanese practice it is possible to get very interesting results by using suitable dyestuffs with a simpler paste.

The most useful dyes for this purpose are the Sulphur dyes, which, as the student will remember, can be applied in the cold, with very short exposure to the dye-liquor, and are fixed firmly by exposure to the air, giving results fast to light and extremely fast to washing. A paste made from wheat flour, thickened a little with an inert powder, like powdered chalk or zinc oxide, will work fairly well, acting as a purely mechanical protection to the fibre. But much better results can be obtained by adding to the paste as much as it will absorb of the easily soluble chemical, zinc sulphate, which acts chemically in resisting the action of these particular dyestuffs.

The Sulphur colors, as before explained, are kept in solution in the dye-bath, by the presence of sodium sulphide, and when this is absent or is destroyed by any cause, the dyestuff is precipitated as an insoluble, inert powder. Now, when zinc sulphate comes in contact with sodium sulphide it at once decomposes the latter, forming a white precipitate, zinc sulphide, which has no action at all on either dyestuff or cloth. Accordingly a paste containing zinc sulphate has far greater efficiency as a resist than any mixture that acts purely mechanically.

Resist stencil pastes can be obtained, in tubes, at moderate prices, but can also be readily prepared by making not too stiff a paste, with wheat flour thoroughly boiled with a saturated solution of zinc sulphate instead of with water, and then stirring into this paste some powdered chalk or zinc oxide, until of the proper consistency for stencilling.

To use this paste, the cloth, as usual, should be washed free from dressing, and after being smoothed with a hot iron, should be slightly dampened. The paste is then brushed through the stencil on to, and into, the cloth, which is then allowed to dry. The dye-bath should then be prepared of Sulphur dyes carefully dissolved, in a separate cup or saucepan, in a hot solution of sodium sulphide and sodium carbonate (soda), and added to cold water in the dye-bath.

A few drops of “Turkey red oil” added to the dye-bath helps to prevent a thick scum from forming on top of the liquor, while the addition of a tablespoonful of salt dissolved in a little hot water helps the rapidity and depth of the dyeing.

Plenty of color should be used excepting for very light shades, for the dyeing should be done just as quickly as possible. For silk some syrup should be added.

The stencilled cloth is then quickly moistened in cold water, placed in the dye-bath, kept there two or three minutes, below the level of the liquid; it is then taken out, the liquor drained off, and after a minute or two, wrung off; the cloth is then shaken out, and exposed to the air, for some ten minutes, to set the color. After this it is well washed in a boiling soap bath, and, as the paste washes out, the stencilled pattern will show light against the dark background.

The whiteness of the pattern depends, of course, upon the skill with which the paste has been applied, and the care taken to prevent it from washing off before or during the dyeing process. It is difficult, though not absolutely impossible, to get as sharp and clear-cut results as those of the Japanese, for instance. But, on the other hand, with a dark background it is often, indeed generally, more pleasing to have the white patterns softened and not standing out too vividly.

In our laboratory we have had considerable success with this process. And some of our friends and students have used it with very good results upon articles of clothing, which, made of linen, calico, etc., must be fast to severe washing as well as to light.

Of course, it is perfectly easy to alter the color of the background, as in other classes of resist work, such as Tied and Dyed work, for instance, or Batik, by either starting off with colored cloth which is protected all through by the resist paste, or else by covering the stencilled and dyed goods, afterwards, with some shade which will soften and harmonize both pattern and background. For this covering shade, which need not be very fast to washing, but must be distributed uniformly over the whole cloth, the student will find the Salt colors very useful.

Discharge Stencilling.—Though it is not certain whether this process is known to, and used by, the Japanese, it is not a difficult matter, with modern dyes and modern chemicals, to get interesting results with it. There are two distinct and separate ways open to the dyer for discharging, i.e., destroying his dyestuffs, whether they are dyed on cloth, or whether, as is not infrequently the case with amateurs, they are present as a stain on his hands and fingers. In each case, however, care must be taken, as may easily be imagined, to use such chemicals as will spare the materials, whether cotton and linen, or nails and skin, while attacking the coloring matter.

(a)Discharge by Oxidation. Chlorine Compounds, Bleaching Powder, etc.—In the first place, chemists have long known that certain chemicals, more particularly the powerful gaseous element known as chlorine and certain of its compounds, have the power of permanently destroying coloring matters by oxidizing or burning them.

At first this was done by using chlorine itself, or a water solution of chlorine. Later, however, it was found that on passing chlorine into some caustic alkali, like quicklime, or caustic soda, or caustic potash, these would absorb immense quantities of chlorine which would be again given out, as desired, on the addition of acid, or even, though very slowly and gradually, by the action of the carbonic acid gas in the air.

The lime compound, which contains more chlorine than the others, and has the great advantage of being dry, has long been known as chloride of lime or as bleaching powder, and has been, and is, commonly used from one end of the world to the other as a quick, ready, cheap source of chlorine either for bleaching or for disinfection. The potash and soda compounds, known respectively as Labarraque’s solution and Javelle water, are less active and powerful than bleaching powder, but have the same general properties.

Over a hundred years ago, very soon after the discovery of the bleaching properties of these compounds, chemists began to use them, not only for decolorizing and whitening raw cotton and linen cloth, but also for discharging the color in patterns from dyed goods. The process was not a difficult one, and is used to this day to some extent in the calico printing mills. The cloth is first dyed to shade, fixed, and dried. The pattern is then printed on with a paste containing some solid organic acid, like citric acid or tartaric acid, dissolved in it. After drying, the printed cloth is passed through a bath of bleaching powder in water, possibly with a little weak alkali added, to be sure that no free chlorine is present; and wherever the bleaching powder meets the acid the cloth is decolorized, but the rest of the cloth comes out of the bath without being much, if at all, altered in color. Of course, on coming out of this bath the cloth must be thoroughly washed to get rid of any traces of chloride of lime, which otherwise, on exposure to the air, would play havoc with the rest of the colors.

This process worked very well with the old vegetable dyes, and, every now and then, some craftsman, of an experimental turn of mind, revives it for stencil work. The dyed cloth is stencilled with a paste made of wheat flour boiled with a saturated solution of citric acid, it is dried, and then passed through a bath of bleaching powder in water, say two or three tablespoonfuls to the gallon. It is generally best to stir in a few drops of a soda solution to the bath, till all smell of chlorine has gone, or else the background may be affected. The stencilled cloth is dipped in this bath, and kept there for a few minutes, until the bleaching process is well under way, and then taken out, and washed in hot soap and water, and rinsed well.

Advantages and Disadvantages of Bleaching Powder Discharge.—The chief advantage of this process is that it is very cheap and the materials can be bought at almost any grocery. The disadvantages are, however, important. As long as it is confined to easily discharged, comparatively fugitive, colors, it will destroy the color all right in the stencilled parts, although the bleaching powder bath is apt to attack the color in the body of the cloth, and the outlines of the pattern are apt to be soft and irregular because of the escaping chlorine, where the citric acid is acting.

When, however, very fast dyes are being used, as for instance, the Vat colors or, indeed, a great many of the best dyes in all the classes, the action of chlorine is very slow, and slight, and, in order to really destroy the color both the acid and the bleaching powder will often have to be so strong that the chlorine set free will destroy the fibre as well. For the term “fastness to light” implies, as a rule, fastness also to oxidation in general, and dyes like the best modern ones which will let the cloth rot away from under them, when long exposed to the weather without changing color, are very apt also to keep their color, even when the cloth isburnt away from under them by the action of chlorine.

Accordingly, this process is distinctly one that needs careful experimentation before it is tried on any important piece of work. There are plenty of dyestuffs among the Salt colors, and also among the Sulphur colors, which discharge well with chlorine. And the calico printer, working, as he generally does to this day, with comparatively fugitive dyes, and weighing accurately both acid and bleaching powder, can generally get good results with it. But there is always the disadvantage, that the least excess of chlorine will attack and tender the cloth, and the better the dyestuff, as a rule, the stronger the oxidizing agent must be to discharge it.

(b)Discharge by Reduction, Hydrosulphite, etc.—The wary craftsman will find the process much less dangerous to the cloth, and not much more difficult, if instead of trying tooxidize the dyestuff, he attempts to discharge it byreducing it; or, in other words, if instead of trying to burn it out, he tries to take the oxygen away from it.

It so happens that in a vast majority of cases a dyestuff becomes decolorized by reducing it, just as well as by oxidizing it. There is, however, a difference. When the color is oxidized, it is burnt up and destroyed forever. When it is reduced, however, it is, in many cases, only decolorized and not destroyed; and on standing in the air it is apt to take up oxygen again, and to regain some, at least, of the original color. On the other hand, while any oxidation process is liable to attack the cloth as well as the color, the reducing agents now in use have no effect upon the materials, even when powerful enough to act on the very fastest dyestuffs.

As before mentioned, the most satisfactory reducing agent at present known to dyers is hydrosulphite of soda, and this can be incorporated in a paste, and used for discharge stencilling. It is, however, as a rule, more satisfactory to use the more expensive, but more permanent hydrosulphite compound, described, in the last chapter, as acting only when heated.

The reducing stencil paste can be easily made by mixing with some “gum dragon” or flour paste, as much as it will hold of a saturated solution of the “Stencil Salt.”

The student should experiment with the different dyes and classes of dyes before attempting a serious piece of work; but in general, all the Salt colors and the Acid colors will discharge readily with this paste, and remain colorless. The Vat colors and the Sulphur colors can also be reduced to colorless compounds, but it is not always easy to wash them out of the cloth after the reduction, and, if they remain in it, they are apt to regain their color, on standing in the air.

The dyed cloth, carefully washed and pressed and dampened, is stencilled with the above paste and allowed to dry. When dry it is steamed, as described in the last chapter, and it will be noticed that when a certain temperature is reached the color will be discharged. As soon as possible afterwards the cloth is to be washed in a hot soap bath to remove the reduced color compound (which, as a rule, has little affinity for the cloth) and to get rid of the paste. Then the cloth is dried and finished.

When trying this process with the Vat dyes it is best to soak the cloth directly after steaming, and before soaping, in a warm bath containing a little free caustic soda (remember this is apt to burn the fingers) because the reduced colors of this class are not, as a rule, soluble in water, and are apt to oxidize again in a soap bath.

Results.—In following up these various experiments in our laboratory we have not used this process in much as the Resist stencilling, but there is no reason why it should not give just as good results. Indeed, the craftsman will probably find, after a little practice, that it is easier to get clear white patterns with this than with the other. It has the disadvantage of requiring the rather bothersome steaming process, which reduces its value for many purposes. Still it will often be found that simply ironing the dried stencilled cloth with a hot flatiron, with a damp cloth between, will cause the reduction to take place quite satisfactorily.

The chief advantage of this process over the other is that, as the dyeing is done before and not after the stencilling, it is possible to get the exact shade of background required. While, in the resist stencilling every minute, almost indeed every second that the stencilled goods are left in the dye-bath, is liable to obscure the pattern. And it is hard to get first-class results, as regards fastness to rubbing and washing, and it is impossible to match shades, when working so hurriedly.

Then, too, this discharge process permits the use of almost every color on the list, while the resist process practically confines the craftsman to the use of the Sulphur dyes only.

Those who are interested in this line of work are advised to try these two processes upon silk, where very beautiful and interesting effects can be produced with but little difficulty. The resist process, using Sulphur colors, gives quiet soft tones on silk, fast to the hardest kind of washing. But brighter shades, equally fast to light, and fairly fast to washing, can be made with the discharge process by using Salt colors.

For ordinary work the Acid dyes, of course, would be used, and these, too, as a rule, discharge readily.

Chapter XVII
BATIK

The last and perhaps the most interesting and most important process to which we shall call our reader’s attention is one which, after being practised in the East for many centuries, has been brought quite recently to the attention of European and American craftsmen.

The term “Batik” is a Javanese word, signifying painting in wax, and the process, somewhat modified, is known to professional dyers and calico-printers by the name of “wax resist.” When in the hands of a trained draughtsman the process has a charm and character of its own, which will warrant the interest now manifested in it, wherever it has been introduced.

History.—Batik was first introduced by the Dutch discoverers of Java, who, in 1648, sent home descriptions, with drawings, of the wonderfully beautiful textiles worn by the people, especially by the chiefs of that country. The art was known and practised in the East long before that time, for in Madras goods were made, by a combination of block printing and Batik, at least as early as the fifteenth century. And in the interior of Java there are some famous old ruins in which are found stone statues of Buddha, supposed to be at least 1,200 or 1,300 years old, clothed in garments the same as those used at the present day; and showing, from their decorations, that they were ornamented by Batik in the same general style of patterns that are still popular there.

During the last few years very careful studies have been made, especially by the Dutch Government, upon this Javanese process, and they have endeavored to introduce it into Europe. It was amusing to notice that in one of the reports issued by the Dutch Government on this subject it was stated that none of the modern dyestuffs could be utilized for this purpose, and that the only colors that could be recommended as fast to light were the old vegetable dyestuffs, applied in the complicated and troublesome methods of past ages. This curiously unscientific attitude has seriously interfered with the success of the process in Western lands, and is only now being abandoned.

Javanese Practice.—Detailed information about the history, technique, and designs of the Javanese process has been set down in a monumental work: “Die Batikkunst in Niederlandisch Indien,” published in Harlem under the auspices of the Dutch Government in 1899. Perhaps of more interest to the non-scientific reader is a short but well-written account of “Battack Printing in Java,” read before the Manchester Literary and Philosophical Society in 1906 by an English chemist, John Allan, who spent several months among the natives, studying the process at first-hand.

According to these authorities the Javanese and, indeed, most of the natives of Malaysia, wear garments simple enough in style and cut, but elaborately decorated with great variety of both color and design. The principal garment, common to both men and women, is the sarong, in shape not unlike a large and elongated bath towel, which, according to the desire and sex of the owner, may be made to serve as trousers or skirt, overcoat or blanket, and is the universal bathing costume. It is made of calico, rarely homespun, almost always imported from Lancashire or Holland, and as the natives, both men and women, are exceedingly fond of bathing, the colors must be fast enough to stand constant exposure to water as well as to the fierce tropical sun.

They also wear head-dresses made from squares of calico, dyed with square centres of plain color and elaborately decorated at the sides; and slendangs, a kind of girdle or shawl, usually made of silk and less elaborately decorated. The costume is completed, for full-dress occasions, by a thin shirt or chemise and a light jacket.

For producing the designs on the sarongs, the process of wax resist is almost always employed by the natives. Unfortunately of late years the Javanese market has been flooded with an immense quantity of cheap and, generally, neatly printed goods made in Manchester and in Holland in rough imitation of the native styles. So it is not an easy matter, nowadays, even in Java, to get genuine specimens of Batik work. These can always be recognized, however, on careful examination by the peculiar and characteristic odor and “feel” of the wax left behind in the cloth, and, better, by the fine irregular “crackle” formed in the dye-pot.

Variations in the Process.—Although there are different methods, the Batik process, as usually meant, is a means of dyeing in which, before immersing the goods in the dye-pot, the patterns are carefully drawn in molten beeswax, applied from a little copper cup with a fine spout called a tjanting. Frequently, however, to save time, the Javanese apply the wax by means of a metal die or block, made by inserting thin strips of sheet brass in a wooden frame, so that the edges of the brass form the desired pattern. These blocks, provided with a handle covered with cloth, are first dipped into the molten wax, and then the excess is removed by pressing against a pad, which is kept warm by being near the fire of the melting pot. The pattern is thus stamped onto the cloth instead of being poured onto it, through a small spout, out of a cup.

This Batik process is sometimes used by native craftsmen in other parts of the Far East. Plate [I], for instance, shows a specimen of East Indian work, part of a long piece of stout cotton bought, years ago, at Liberty’s in London, with an elaborate design made with molten wax, applied by brush or tjanting. Even in the plate the characteristic ‘crackle’ shows plainly.

Wax.—In Java, the wax used for pouring is a mixture of paraffin and beeswax, or an impure wax imported from Japan for this purpose. For stamping the patterns it is necessary to use a stiffer wax made from rosin and paraffin, sometimes mixed with varnish gums.

Dyes.—The principal colors used are indigo and a beautiful golden-brown dye made from the bark of the mango tree. The combination of these gives a black, so that the fine old sarongs usually contain white, blue, brown, and black. Indigo is dyed first, and, before dyeing, all the cloth, excepting that which is to come out blue or black, is carefully covered with the wax. After the indigo bath (the Javanese use a fermentation vat) the color is set by oxidation. The old wax is then all washed off with boiling soap and water, and after drying, the wax is again applied to all parts, whether white or blue, which are not to receive the brown dye. The latter is made from a strong, syrupy extract of bark, and is used without mordanting, the color being set by exposure to air. As the dyes must be used cold, to avoid melting and obliterating the pattern, the goods are usually dipped in each dye-bath and exposed, several times, before reaching the desired shade. After the final dyeing, the wax is removed by a hot bath of wood ashes or soap, and the garment is pressed out ready to wear.

When a red color is desired, the natives use a variation of the old Turkey red process, dyeing with madder or munjeet upon cloth mordanted with alum and oil. The wax in this case acts as a resist against the alum mordant, which is applied cold, and thus prevents the dyestuff, which is applied at the boil, from coloring the cloth in the protected portions.

Cloth.—The cloth used for this Batik process is strong common calico, but, before beginning to wax it, they give it a careful treatment, to improve both its texture and its ground color. For a period of several days they alternately soak it in castor oil, wring it out, boil out the oil with soda lye, and expose it to the blazing sun; until finally it becomes soft and smooth, and has a pleasant tan color which goes excellently with the brown, blue, and black dyes.

The peculiarity of all these Batik goods, whether from the East or made at home or in Europe, is the characteristic “crackle” effect, due to the breaking of the wax upon the cloth in the process of dyeing, thereby admitting the color to the protected cloth in fine lines and streaks. This distinguishes the wax resist work from the previously described paste resist, which if desired will leave a smooth, clean, white background, or if applied more lightly will give backgrounds shaded more uniformly and without so many irregular lines of color.

This crackle effect, so generally admired in the West, is often by the Javanese considered a defect, and a sign of poor workmanship. It can be largely, if not wholly, avoided by adding a large proportion of rosin to the wax, by batiking the cloth on both sides, and by dyeing the goods with as little crumpling as possible.