In preparing opalines, immerse a photographic print in a 5-per-cent. solution of gelatine. Warm the glass, and pour on it in a pool a portion of the gelatine solution; immediately lay the print, face down, upon this, and squeeze out any air bells. The glasses are generally edged round inside with a rim of gold paint. The prints should be cut slightly smaller than the glasses, and be just large enough to cover the rim. Before the print dries a piece of waterproof paper is mounted over the back. Finally, the strut is affixed with glue.