Lay the glass over the pattern or copy you wish to paint from, such as flowers, birds, wreaths, etc., then with a fine pencil brush, or a common writing pen, trace all the outlines of your pattern as well as possible on the glass, using for that purpose black paint made from lampblack and copal varnish; if too thick, add a little turpentine. When this is done, paint all the glass outside the picture, or that part not occupied by your drawing, with the black paint, same as used in making the outlines, only a trifle thicker. This will give your picture a neat background; other colors can be used, but this gives the best body, and is the most appropriate, contrasting well with the other colors to be used in the picture.
Let it lay until well dried, so the black will not unite with the colors you are about to use. Now, with the glass still remaining over the copy, you may commence applying the paints, if the tracing lines are dry. If you are painting a red rose, use carmine and flake white, Prussian blue, and chrome yellow for the leaf, etc., using a small camel-hair brush. Continue in this way until you have used all the colors which appear in your copy or picture underneath, which remains there to guide you, and the pen lines upon the glass to separate the colors. When the first color is perfectly dry, apply the second, and so on until you have completed all the work which the copy demands, using your own judgment in the matter, applying them as they appear in the picture you are working from.
When the painting is done and dry, cover the back of the transparency with copper or tin-foil crinkled, which gives it a sparkling, crystal-like appearance. It is now ready for framing. In placing it in the frame, be careful and not press the backboard too close on to the foil, or it will destroy the brilliant effect in the picture.
The colors used in this kind of painting must be transparent oil colors, with the exception of the background.
For white, use ground silver or flake white; for blue, Prussian blue; for pink, mix scarlet lake and silver white; orange, mix chrome yellow and scarlet lake; for red, use scarlet lake, crimson lake, or carmine; for green, mix Prussian blue and yellow lake; for purple, mix red and blue. Use the best tube paints and camel-hair brushes.
No style of painting has yet been produced which shows transparent colors to such advantage, and never fails to attract attention and admirers wherever introduced.
It is called Oriental from the fact of its producing effects of coloring equal to the colors of Oriental flowers, and the plumage of Oriental birds.