Mixing forms an important part of sign work, which, however, is considerably lessened of late, by reason of several manufacturers having placed on the market prepared colors which meet the requirements satisfactorily. I would advise their use if it is possible to obtain them.
One very important thing is, do not use oil paint on cardboard. It does not work well and will cause much trouble. No experienced marker uses oil paints, unless it is black asphaltum to fill in and outline letters; such as several large department stores are using at the present time. The glossy effect of this class of work is considered by many to be very attractive.
The drawback to this method is, the cards require a double handling and consequently the work is very slow.
Drop black, in distemper, is the cleanest and most handy preparation for card work. It is sold in most cities in jars containing one pound. All that is required for making it ready is a little dissolved gum arabic and water.
Take your palette knife and mix these thoroughly on the piece of glass, to about the consistency of a thick paste; it will then be ready for use.
All colors can be purchased in this form. To those who would prefer to mix their own paint here are given a few hints on mixing.
BLACK PAINT.
Lamp-black, ground thoroughly with water and gum arabic, a few drops of alcohol added, will make a fairly good black. All dry colors can be mixed in this way.
WHITE PAINT.
Fill a tin cup about ¼ full of whiting, thin it with water, add ½ ounce of pulverized glue—boil slowly, continually stirring until the glue is thoroughly dissolved; this, when cool, will make an excellent paint for dark boards.