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Student Sourcebook 2007
International School of
Painting, Drawing, and Sculpture in Umbria, Italy
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Cold pressed linseed oil - for grinding pigments. Sun-thickened oil and stand oil - used for media. Oil of turpentine. Venice turpentine. Mastic and dammar - preparation: The resin is first pulverized and then it is put into a gauze and hung in a wide-necked glass, partly filled with rectified oil of turpentine, so that the resin hangs to about the depth of an inch in the turpentine. The proportion is 1:2.
Painting media are used for thinning oil colors during the process of painting. The painting media used in one and the same picture should preferably be the same in all its layers. A composition of: oil of turpentine, dammar or mastic, linseed oil, stand oil and Venice turpentine. One can decide on the composition of a painting medium for a definite purpose. The lower layers should be rich in pigment and poor in binding medium, so that they will dry rapidly and well. One should paint fat over lean.
A correct underpainting must be meager in quality. Only in this way is it possible to paint over it successfully. It must be rich in pigment and consequently in body color, and proportionately poor in binding medium, so that it will have a mat effect when dry. One can mix with the tube paint a quantity, about 1/8, of dry pigment.
Overpainting: Glazing with resin mixed with fatty oils or Venice turpentine with thickened oil. It is of advantage to begin with semi-opaque glaze, and also to give each color at least a small addition of white.
Intermediate varnishes serve to moisten the dried color layer of an underpainting. Resins, such as mastic or dammar, painted very thinly either by themselves or with additions of fatty oils in moderation, thinned with some oil of turpentine, are good intermediate varnishes.
Tempera is an emulsion. An emulsion is a watery, turbid, milk-like mixture of oily and watery constituents.
One measure: the contents of the whole egg, an equal measure of oil, thickened oil or resin varnish, stand oil etc., and up to two measures of water. The order of ingredients is important, first oil, then water. Oils or thickened oils, or resins, can be used in any desired proportions, for example, 1/3 linseed oil and 2/3 dammar, or 3/4:1/4. With oils and oil varnishes the emulsion is fatter, with varnishes thinner. One can also make an emulsion with the yolk alone.
Egg white can be used as a painting medium. Egg white, beaten to a froth, makes the color pigment appear pale. Egg white mixed with thick dammar or mastic serves as a medium for oil painting.
40 gm casein are first mixed with very little water, then 1/4 liter moderately warm water is added. In the meantime 10 gm ammonium carbonate are dissolved in a few drops of water, and after all the lumps have been pressed out, the solution is poured into the casein. Resins, varnishes, egg and also light stand oil are all used in combination with it. Casein Cremnitz white mixed in equal parts with oil. Cremnitz white furnishes a very quickly drying white of high covering power.
The picture in the beginning was outlined on the white ground with tempera color. The tempera white should have body and a broad, flat effect. Glazes should be applied quickly and with a broad brush. One may continue to alternate heightening with tempera white and oil color without interruption or wait until the last painting is dry. To move from light to dark is the better method. Another version of the mixed technique: the underpainting was made of a mixture of equal parts of casein white or egg-tempera white and thickly ground oil white.
Watercolor painting is based on the glazing quality of colors, which is applied in very thin layers. All the light comes from the ground--which is the paper.
This is an easy to make spray fixative that works better than the store-bought aerosols and costs much less. Take 2 sheets of fish gelatin (used for cooking; comes in thin, transparent sheets) and dissolve in a cup of hot water and put in a spray bottle. Fill bottle to half with water (250 ml) and half (250 ml) with denatured alcohol. Tape or tack your drawing down to prevent the paper from curling, and spray on 2 coats, so it gets wet. (Rinse sprayer after use, or the gelatin will block the little hole.) In Italy, the alcohol is pink, but dries clear.
Don't try this the first time with anything precious or irreplaceable.
Working on a floor or a table, stretch a piece of canvas somewhat larger than the paper on a solid flat surface (plywood). Gesso it. Allow it to dry completely. Lay a piece of acetate on a flat surface (a garbage bag would do), and put the painting on it, face up. Cover it with a lot of water. Turn it over. Cover the back with a lot more water. Place another piece of acetate over it, to keep the air out while the painting absorbs all the water it can. Depending on the thickness of the paper, this step can take 20 minutes. Soak the stretched canvas with water. The canvas surface and paper surface should be as much alike as possible, so they shrink together as they dry. Apply gel [Liquitex Gel] carefully to the back of the painting and to the front of the canvas. Don't miss any spots on either surface.
Once the painting is put down on the canvas, it can't be moved, so it must be carefully placed. Slowly unrolling from one end is a good way. All the air must be quickly removed from between the paper and canvas, but a layer of gel must remain, so a print roller isn't a good idea. Wet your hands and use your hands and fingers to push the air to the edges of the paper. Gel will cover the front of the painting by the time you're done. It will seal and protect it. Watch as it begins to dry and if any air bubbles appear, move the air out to the edge. The thinner the paper, the easier the process. The picture can be removed from the board and stretched the next day.
In three separate containers,
Add the egg mixture to the white mixture and separate in half. The mixture should be fluffy. Add an equal amount of titanium white from a tube to one of the two parts, and a few drops of the wax mixture.
The first batch is White Tempera; the other batch is Erasing White. Erasing white is good for covering up large areas. White tempera should be painted on a wet surface (by wetting with medium or retouch varnish), dries quickly and is good to glaze over. For texture, add some marble dust to the white pigment. Put water on top of the white at the end of the day to keep it fresh.
Mix together equal parts titanium white powder, gesso di bologna (chalk), water and glue, and add a few drops of linseed oil to prevent cracking. Works like store-bought gesso and costs less (at least in Italy). Water, glue and pigment can also be used for colored grounds (substitute earth color for white) or glue-painting. Gesso di bologna is an extender that can be used when making oil paint with powdered pigments. It gives the paint body without affecting the color intensity.
Damar resin and beeswax
This formula produces a soft paste; if you prefer a solution, stir in twice the amount of turpentine while the solution is still hot. Combined on the palette with tube oil paints, the medium thickens the paint and produces a soft finish. A thin film dries in 30 minutes.
Wax Paste
When you wish to thicken (or make buttery) the normal oil paint consistency, nothing is better than beeswax for the purpose. Very thin layers, or scumbles, can be applied with this medium. Dries in 30 minutes.
Wax, damar resin, oil
For a thick, buttery, but light consistency in an oil paint, wax combines well with fast drying soft resin and heavy oil. Sets immediately and dries in 30 minutes.
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Student Sourcebook 2007
International School of
Painting, Drawing, and Sculpture in Umbria, Italy
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