How to Transfer a Photographic Print to Glass.
To transfer a photographic print to glass for painting or for other purposes, separate the paper print from the background by steaming it; dry thoroughly, and having given the warmed glass an even coating of clean balsam or negative varnish, place the face of the print on the surface thus prepared, smooth it out and let it stand in a cool place until the varnish has hardened. Then apply water, and with a soft piece of gum-rubber rub off the paper so as to leave the photographic image on the varnished glass.