To Paint the Sliders of Magic Lanterns.

Scientific American 41, 1.7.1848

Provide a small muller and a piece of thick ground glass five or six inches square to grind the colors on, also a small pallet knife and a few bottles to put the colors in. For a red color get a little scarlet lake, and for blue a little Prussian blue. For green use purified verdigris ground with a quarter of its bulk of gamboge, abnd for brown use burnt umber, and for black, burnt sienna black. THese are the only colors that are truly transparent anf fit for panting sliders. Having all these colors ready, grind them in the balsam of fir mixed with half its bulk of turpentine; mastic varnish will do very well, but the balsam is the most beautiful. To paint the glass black round the painting, dissolve asphaltum in turpentine and mix with lampblack. WWhen the colors are all ground they must be put in separate bottles and sealed, and when they are to be used a little bit is taken out at once on a piece of glass, just as much as is needed at once, as it quickly dries. If the color is too thick it must be diluted with turpentine. To paint the sliders, the subject must be designed on paper and the paper put under the glass and the glass painted above it accordig to the design on the paper underneath.