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Stars containing nitrate of strontian must be damped, either with lac solution, or wax solution; anything containing water destroys the colour. Nitre stars may be damped with gum water, dextrine solution, or thin starch. Most other stars with either of the solutions. Crimsons and greens will mix with boiled linseed oil, but they cannot then be matched, as oil renders meal-powder almost uninflammable. With all stars, not a drop more of the solution should be used than is sufficient to make the composition bind; and it is advisable not to damp more than half an ounce at a time; this is particularly the case in using the lac solution, as it dries rapidly; and if a large quantity of composition is damped, and gets dry, and has to be damped over and over again, it becomes clogged with the shellac, and the colour is deteriorated. If it should get dry, and require a second damping, it is best to use pure spirit only, the second time.

Before mixing compositions, every article should be as fine as wheaten flour, and perfectly dry. Nitrate of strontian, if purchased in the lump, should be set over the fire, in a pipkin; it will soon begin to boil in its water of crystallization; it must be kept stirred with a piece of wood, till the water is evaporated, and a fine dry powder left. A pound of crystals will yield about 11 ounces of dry powder, which should be immediately bottled. Even then, if used in damp weather, it is best dried again, and mixed with the other ingredients while warm. This second drying may be in a 6-inch circular frying-pan.

Articles, separately, may be reduced to powder, with the pestle, in a mortar. See that it is wiped clean every time, as there is danger of ignition with chlorates and sulphurets. When the articles are to be mixed, they may be put into the mortar, and stirred together with a small sash-tool. A ³⁄₈ inch is a convenient size. The mixture must then be put into a sieve, and shaken in the usual way; or it may be brushed through with the sash-tool. Return it to the sieve, and brush or shake through again. As it lies in a heap, level or smooth it with the blade of a table knife, or any straight-edge; if thoroughly mixed it will present a uniform colour; if it appears darker in one part than in another, it must be sifted again. A sieve with a top and receiver is very desirable, as nearly all mixtures are either black or poisonous; the dust from star mixtures is very injurious to the lungs. If a top and receiver cannot be readily purchased, both may easily be constructed out of a sheet of millboard, fastened with a bradawl and waxed yellow flax, and neatly covered with paper.

Mixtures may be damped on a Dutch-tile, a marble slab, or a slate without a frame. They may be stirred about with a dessert knife, pressed flat, and chopped, or minced as it were, and again pressed flat.