Valuable Secrets concerning Arts and Trades:
or Approved Directions, from the best Artists, for the Various Methods...
Printed by Thomas Hubbard,
Norwich, 1795Chap. V. Secrets concerning colours & painting.
§ VIII. Preparations of colours of all sorts for oil, water, and crayons.
1. Take half-a-pound of the finest Brasil wood you can find. Cut it in small bits, and pound it in an iron mortar. Put this in a new and glazed pipkin; pour over it two quarts of strong wine vinegar. Let this infuse without the assistance of any heat for three whole days. Boil it next for half an hour, then add one ounce of pulverised Roman alum, and boil it again for the space of three quarters of an hour, that the alum may the more perfectly be dissolved, and the stronger the colour.
2. Take the pot off from the fire; and, rasping the softest part of a dozen of found or cuttle fish bones, add this powder to it. Replace the pot on the fire, and stir the contents, with a bit of cane, till you see a froth rising on the top of the composition; when immediately taking the pot off from the fire again, you cover it with its lid, and let it stand for a week. During that space of time you must, however, carefully stir this matter, with the cane above-mentioned, four times a-day.
3. Have next a glazed pan, which you fill with cry sand as high as three fingers from the brim. In this sand put your pot halfway in. Place all on a charcoal fire, till it nearly boils; then, taking the pot off from the fire, run the liquor through a clean cloth. Put it indifferent retorts, and set them halfway in your sand again, which, by this time, ought to be quite cold. Replace all on the fire, as before, and keep it there till it begins to simmer; then, taking it off from the fire, let it cool, and the lake is done. But it must not be used till twelve days after, during which time let it rest.
Note. When the tincture is in the retorts, you may, if you chuse, put in each of them half a gill of lye, made with vine-branch ashes. - When you put the powder of cuttle-fish bones in the tincture, you must take care it is warm. The residue which is found at the bottom of the retorts ought not to be thrown away, as it is very good to paint in water colours.
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