French or Yellow Ocher is in fair demand for tinting kalsomines and for fresco or distemper work in general. For this purpose the citron shade, J. C. L. E. S. of French ocher is preferable, and sixty-five parts of the dry pigment, well mixed with forty parts water and then run through a good stone mill, will produce 100 parts of paste, to be put up in the usual way in glass, or, if required in quantity, in earthen jars or wooden kegs well sized inside. Tin pails are not well adapted for this class of goods because of the formation of rust.
Golden Ocher, both pale and deep, are also found in lists of distemper colors, being useful in producing the richer yellow tints. For the pale shade, the citron ocher, say fifty-seven parts, eight parts of pale medium chrome yellow and forty parts water, will produce 100 parts of paste, while for the dark shade, fifty-five parts of strongest J. F. L. E. S. ocher, ten parts of a light shade of orange chrome yellow and forty parts water will result after grinding in the production of 100 parts paste.
Dutch Pink, English Pink or Italian Pink, under whatever name it may be called for, is also very useful as a water color, for the reason that it enables the decorator to obtain effects that he cannot produce by the use of ocher or raw sienna in composite colors, while yellow lake would prove too expensive. The percentages of pigment and water required for mixing and grinding Dutch pink depend very much upon the base on which the dyestuff is precipitated, but figuring on sixty parts pigment and forty-eight parts water for 100 parts paste will prove a safe average.
Chrome Yellows, light or lemon, medium, dark or orange, are also in fair demand, and when a color making establishment is connected with a color grinding factory it is, of course, a decided factor in economy to place the pulp from which all but say 35 per cent of the water has been removed by settling or pressing on a mill to give it one, or at most two, runs in order to break up any little particles that usually form when the yellows are precipitated. Thirty-five per cent by weight of water would be the average in the pulp, and this will mean about 40 per cent for the medium, but not over 30 per cent for the light, or lemon, and dark, or orange, shade. However, the color grinder who does not have a color making department connected with his plant will mix the dry yellow in water and run it through a soft stone mill until the paste is fine and of proper consistency. These pigments, being rather heavy, are apt to settle when ground with excess of water, hence it is necessary to scoop off the surplus after permitting the finished goods to set over night. For the light and dark shades seventy parts dry pigment and thirty-five parts water, and for medium chrome yellow sixty-five parts dry color and forty parts water, should, when ground, render 100 parts paste in each case.
Permanent Yellow or Zinc Yellow is fairly important in the line of distemper colors and should be found on the list. The proper proportions for 100 pounds of paste in water is to mix seventy-six pounds dry color with thirty pounds clear water and run through a clean stone mill.
Aureolin or Cobalt Yellow, being partly soluble in water, should be omitted from the list of water colors.
Cadmium Yellow is too expensive for use in this connection, therefore not called for by the trade.
True Naples Yellow is not used in distemper painting.