1526. Third.—Place the engraving face down and sponge it gently with water; then press the frame firmly and evenly down on; leave it till entirely dry (not by the fire), and it will become even and tight.
1527. To make the Grecian Varnish.—Take one part turpentine, two parts alcohol (90 proof), three parts balsam of fir, and mix.
1528. To use the Varnish.—Pour sufficient spirits of turpentine on the back of the picture to moisten it well, then put on the varnish and rub it thoroughly with a stiff brush, and continue to apply it until the picture is perfectly transparent.
1529. Spots.—Leave the picture for twenty-four hours, after which if white spots appear, showing that the varnish has not been effectual, repeat the process. Sometimes it has to be done several times.
1530. Drying.—Place the picture, face downward, where it will be free from dust, and leave it three or four days.