There are three principal modes of oil-painting on glass, as follows:

Non-Transparent Painting on Transparent Glass. In this mode the materials are the same, and the method the same, except in one particular, as that employed in painting on the front of mirrors. The sole particular in which it differs from this kind of mirror painting is this: it must be much less transparent in the shadows and half tints, for the reason that it has no silver foil or ground; the paint, therefore, must have sufficient body in every part to prevent anything dark or bright behind from being visible through it, and thus affecting the coloring. This mode is much used for decorating unsilvered plates of glass to be inserted as panels in screens. As, however, the back of the screen is not covered in the usual way, if both sides are likely to be seen, and it be found desirable to hide the unpleasant appearance of the back of the painting, this can only be done by repainting on the back of the glass the subject on the front.

The outlines must be made to coincide with those showing through and a study of the subject should be used to fill in within the outlines, but less finish will usually suffice.