Red Printing Ink.
Red printing ink may be made in this way:—Boil linseed oil until smoke is given off. Set the oil then on fire, and allow it to burn until it can be drawn out into strings half an inch long. Add one pound of resin for each quart of oil, and one-half pound of dry, brown soap cut into slices. The soap must be put in cautiously, as the water in the soap causes a violent commotion. Lastly, the oil is ground with a sufficient pigment on a stone by means of a muller. Vermilion, red lead, carmine, Indian red, Venetian red, and the lakes are all suitable for printing inks.
To Prevent Electrotype Blocks from Warping.
To prevent electrotype blocks from warping, shrinking or swelling, place them in a shallow pan or dish, cover with kerosene oil and let them soak as long as possible, say three or four days. Then wipe dry and place in the form. After the first two or three washings they may swell a little; if so, have them carefully dressed down, and after that you will have little or no trouble with them, and can leave them in the form just as you would were they solid.
Black Printing Ink.
To make a good, permanent black printing ink, take
| Balsam copaiva | 9 oz. | |
| Best lampblack | 3 oz. | |
| Prussian blue | 1½ oz. | |
| Indian red | 0¾ oz. | |
| Turpentine soap, dried | 3 oz. |
Grind on a stone until extreme fineness has been obtained. This ink will work clear and sharp, and can easily be removed from the type.