Illumination and Its Development in the Present Day

by Sidney Farnsworth

Fig. 39.

The following is a good method of quickly writing a poster. A sheet of paper is ruled, in the manner shown in [Fig. 39], with a soft black-lead pencil. The lines should be ruled lightly and fairly closely together. If the poster is to be written on thin paper, it is not a bad plan to rule these lines boldly in ink on another sheet, so that if this is placed under the paper upon which the poster is to be written these lines will show through quite plainly enough to act as a guide to the writer. It is a good practice to have a number of sheets of various sizes ruled out, so that when a poster is required of a given size one of these can be utilised and the poster written quickly.

The lettering may be roughly sketched in either with a soft black-lead pencil or a piece of charcoal. It may then be written straight away with the pen or brush. When the lettering is quite dry the pencil-marks may be cleaned off with bread or soft rubber, or if charcoal has been used this may be dusted off quite easily; the poster is then complete.

As is plainly obvious, the poster shown in [Fig. 40] is produced by means of the pen. The best type of pen for poster-writing is undoubtedly the reed pen, especially if the writing is needed to be fairly large. When this form of pen is used it is advisable to cut it with a fairly long slit; this will ensure the pen working much easier.

When writing with black and red inks, one pen should be kept for black and the other for red. If this is not done, the pen should be carefully washed after it has been used for black ink before using red ink, otherwise the black left in the pen will mix with the red and make the colour dirty. Undoubtedly the best way is, as already mentioned, to use a separate pen for each colour.

Fig. 40.

As most posters have to be exposed to the weather it is well to use only fixed inks. Fixed inks are generally prepared by being mixed with shellac which is dissolved in a solution of borax. Ordinary water-colours may, however, be made waterproof quite easily by the following method. A saturated solution is made of some bichromate of potash, and a few drops of this solution are added to the colour just before using it. As this chemical makes a bright orange solution it will alter some colours slightly, but for blacks and reds it will not be noticeable. This chemical has the property of making glue, size, or gum insoluble when it is mixed with them, after exposure to the light, and, as water-colours are mixed with gum, it has the same effect in this case. If, therefore, the poster be exposed to the light of the sun for a short period after it has been written, the colour quickly becomes insoluble and therefore waterproof. The best way is to mix as much colour as will be required in a small saucer, adding the bichromate solution. It is quite easy to understand that if any of this colour dries in the saucer it will have to be thrown away, as the light quickly affects it when dry and it will be quite useless owing to its insolubility. Possibly it will be noticed that a yellow stain will show on the back of the poster when the bichromate has penetrated. As, however, in this case one side only of the paper is used, this will not matter in the least.

Larger posters may be written with the brush (see [Fig. 41]), or partly with the pen and partly with the brush. A brush that is very suitable for quick writing is a Japanese brush like the one illustrated in [Fig. 41]. This can be used almost in the same manner as the pen, and it is possible to write very quickly with it.