When the raw canvas has been stretched or mounted on a panel, it should be painted with a simple solution of glue water (2 ounces glue to 1 quart water). The best glues arc those made of hide, rabbit skin or gelatin. All come in thin sheets and should be soaked in a little water overnight, then heated slightly to dissolve them. Add the remaining water after the glue is dissolved.
There are many ways of priming a canvas. A simple gesso ground which can be used on either linen or panel may be made as follows:
1 quart glue water (made as above). 1 pound whiting powder. 1 pound zinc powder (or 2 ounces titanium dioxide).
Mix thoroughly and paint very thinly on canvas with a brush or smooth on with a knife. Several coais may be applied, but each must be given time to dry. The titanium has more covering power than the zinc white, but does not give as white a surface. This ground is suitable for tempera; if it is to be used for an oil painting it is advisable to add up to 8 ounces of open kettle boiled linseed oil or thickened linseed oil, stirring it drop by drop into the gesso when the latter is cool. The above quantities will make enough gesso to prime about six 25- by 30-inch canvases.
An excellent picture varnish may be made by dissolving one part of either mastic or damar resin in two to four parts of rectified turpentine (by weight). The resin comes in small lumps. Select those with the fewest impurities, grind to a powder, place in a bag of linen or cheese cloth, and suspend freely in a jar three-quarters full of rectified turpentine. Cap the jar to prevent evaporation.
b. Damar will dissolve in a few days, while mastic may require several weeks. The process can be hastened by melting the resin with the greatest care in a double boiler over a low flame and adding the turpentine in small quantities. However, the cold method provides better varnish and avoids the very great danger of combustion. If the varnish is muddy, add a few drops of methyl alcohol, which will clarify it immediately.
A simple and entirely satisfactory oil tempera may be made by mixing one egg (yolk and white) with an equal measure of thickened oil or of oil damar varnish in equal parts. To this is added 1 to 11/2 measures of water. The oil used should be either stand oil or sun-thickened oil.
It is important that the ingredients be mixed in the following order. Beat the egg to a fruth, then combine with the oil, or oil and varnish mixture. Shake vigorously. Add the water and shake again until an emulsion is achieved. Your ground colors may then be added to this medium after being worked into a stiff paste with a very little water. If only oil is used in the above mixture, the medium will be heavy and slow-drying; the addition of varnish makes it thinner and accelerates the drying. The proportions may be altered to suit the taste of the individual.
Many kits containing a selection of paints and other equipment may be purchased at art supply stores, but these often fail to provide certain indispensable tools. Also, they are generally more expensive than the same items purchased separately. For the assistance of the beginner, the following lists of equipment have been drawn up.
The majority of oil paints may be bought in cither student quality or finest artist quality. The former are quite satisfactory for most purposes and should be bought, for economy, in the studio-size tubes (except zinc white, which it is advisable to buy in 1-pound tubes). A simple selection of colors for the beginner should include the following: cadmium yellow (light) ;yellow ochre earth red ;alizarin crimson cadmium red ;viridian green permanent blue ;ivory black raw umber ;white (titanium or zinc) burnt sienna
For a more complete palette, the following additions are recommended: cadmium yellow (medium) yellow ochre deep cobalt green cobalt blue French ultramarine cerulean blue cobalt violet verte emeraude terre verte burnt umber
Taste in brushes varies greatly, but the following selection will cover the needs of the beginner.
Flats (white bristle brushes) one each of the following sizes: Nos. 2, 4, 6, 8, 10. A wider range can be achieved by adding one each of the following:
Brights (white bristle brushes) Nos. 2, 4, 6, 8, 10.
Rounds (white bristle brushes) Nos. 4, 6, 8. Flats (sable oil and tempera brushes) Nos. 6, 12, 20.
Rounds (sable oil and tempera brushes) Nos. 8, 10, 12.
The following are recommended as invaluable aids to the artist:
(1) Palette knife of the general shape illustrated
(fig. 259). It has a flexible steel blade set in a wood handle.
(2) Single palette cup for oil or turpentine (fig. .260).
single palette cup
(3) ;Bottle rectified turpentine.
(4) ;Bottle pure or sun-thickened linseed oil.
(5) ;Palette. This may be purchased, but a sheet of glass or a square of masonite or other wall board which has been rendered non-absorbent will prove satisfactory.
For a more complete painting kit, or for the special purposes indicated, the following items may be added: