FLASHED GLASS SIGNS.
Flashed glass is clear on one side and colored on the other; the colored glass forming only a thin film on one side of the clear glass. We can make elegant signs on this glass by etching the letter through the colored portion of the glass, making the letters clear and the background colored; or by etching out the background and leaving the letters colored. Lay out the letters on paper, and place it under the glass as a guide to work by; then, with asphaltum varnish cover the background and leave the letters free and clear; in other words, “cut around them.” If you want a clear background with colored border and colored letters, cover the letters and border and leave the background free and clear. Then melt some beeswax, and when it begins to cool, take up a small portion of it with a putty knife and scrape it off on the edge of the glass, and repeat the operation until a wall or dam is made all around the glass, to hold the acid you are about to put on the glass, from running off; then pour on a little hydrofluoric acid, and it will etch out the colored glass not covered by the asphaltum in about one hour; then you can pour the acid back into your bottle, to be used again. Next wash the glass by pouring water over it; then scrape off the wax, and take off the asphaltum with turpentine. Some painters use a varnish made by melting together equal parts of paraffine and asphaltum and thinning to working consistency with turpentine.