=Direct Application of Color.=—In this intricate work it will generally be found almost a necessity to apply colors through a stencil in the form of a paste, for when the coloring liquid is thin it is very apt to run under the edges of the paper and spoil the design. It is best to thicken it with a little “gum dragon,” a carefully prepared paste of gum tragacanth, to which the coloring matter, and any reagents that are needed, can be added. The nature of the reagents and the class of dyestuffs used depends, of course, upon the kind of material to be stencilled. =(a) Leather.=—While not very often used, students interested in leather work will find a carefully designed and neatly cut stencil a most useful medium for obtaining interesting and beautiful effects. The leather, whether bark- or alum-tanned, should be carefully dampened, and then stencilled with a paste containing Basic colors dissolved with a drop of acetic acid. On drying, the leather should be finished as usual. The Acid colors are not nearly so satisfactory for stencilling, although, as already mentioned, they are often advantageous for dyeing, rather than staining, leather fast colors. =(b) Silk.=—Silk may easily be stencilled provided the pattern is not expected to be fast to washing. 1. _Acid Colors._—These dyes, mixed with a few drops of formic or acetic acid, will color it well, but to make the dyestuff penetrate it is advisable to steam the goods. This can be done with a teakettle provided with a wing tip for the spout, made of tin, or by heating a flatiron or iron plate very hot, and pressing the stencilled goods back down against it, with a damp cloth in between. The hot steam thus produced, passing through the goods, melts the paste and drives the color down into the fibres and sets it there, so that, later, the stencilled goods will stand light rinsing in lukewarm soap and water without running. 2. _Salt Colors._—Faster results can be obtained, on silk, with a paste containing salt dyes, with a drop or two of acetic acid, provided the silk is thoroughly steamed afterwards. 3. _Basic Colors._—Basic dyes may be used on silk as on wool, leather, or any other animal fibres for direct application, the dyestuff dissolved with a drop of acetic acid, being added to the paste, and then brushed in and, preferably, lightly steamed to sink the paste down into the fibres. These dyes, however, with but few exceptions, are not fast to light, and applied in this way are not fast, either, to washing. By adding some reagents to the paste, however, a Basic stencil paste can be formed which gives colors on silk which will stand active scrubbing excellently.