MIXING QUICK COLOR.
A quick-drying color can be slowed up and made to dry to any required time without injuring it, while if ground in a slow drying preparation, it cannot possibly be quickened without injuring more or less the working and covering properties. The working is certainly important, and the covering more so. The covering property should be strong, because the fewer coats of color on a job the better. Thus a quick dryer saves both labor and time.
Japan colors are best when ground stiff, or with barely enough liquid to bind them firmly, because after being reduced to thinness with turpentine alone they will cling to the surface and will not smut. The color will then have its greatest covering power. Now, by the addition of sufficient pure raw oil to give the best working property, and being also made to dry flat, the color is as near perfection as possible, and the further addition of anything weakens the covering power. When an excess of japan is used in grinding, the color is thin, there being less pigment to the pound; and it is of less value to the consumer, while it affords more profit to the manufacturer than when prepared as it should be.