Painting techniques – oil painting, cleaning, technique and history
In museums and private collections you sometimes see paintings that are still relatively new, but already cracked or peeled off. That’s because most art academies have not paid attention the last hundred years of material and technique. There exist books, but primarily based on outdated standard works.
For the specific needs of the artist, but also for the insights of collectors, restorers, curators and serious amateur painters, Chris Herenius did research for twenty years in the laboratory of the Minerva Academy in Groningen. The results are reflected in the new textbook, “Het Kunstenaarsboek” (The Artist Book), where the latest developments are incorporated in painting. I immediately purchased a coy and have never regretted it. I check it regularly.
I have been working for several years now with homemade medium consisting of walnut oil and turpentine (but white spirit is also an option), much to my satisfaction. The tip I found on the Internet a couple of years ago.
My favorite color is Oudt Holland Scheveningen Oil, now called Old Holland Classic Oil Colours. The Oudt Holland, founded by professional artists, has existed since 1664. During this time, traditional knowledge was bundled into guilds. In the painters’ guild the master taught the journeyman and the apprentice made the paint for the journeyman and the master. When the journeyman was found to be competent enough, he became master. The Oudt Dutch originated from those roots. Still this high-quality classical oil is produced according to traditional recipes.
The only manufacturer who makes colors based on walnut oil is M. Graham & Co. in the U.S. Not available in the Netherlands and as far as I know not in other European countries.
Painting techniques – oil painting
To avoid solvents while cleaning, use Walnut oil in place of turpentine or odorless mineral spirits.
Walnut oil removes color from the artist’s brush, palette or hands as effectively as odorless paint thinners without creating a hazard to the individual or the environment. Walnut oil is a natural vegetable oil that does not evaporate neither does it remove essential oils from the artist’s skin or the hair of the brush.
To clean brushes while painting, keep two small jars (one “dirty”-one “clean”) filled with Walnut Oil-a small piece of screening can be kept in the jar bottom to facilitate removal of color from the brush. As it becomes necessary to clean your brush, wipe the brush with a rag, dip into the first jar of oil rubbing vigorously to dislodge any color, wipe the oil from the brush and dip the brush into the second jar to remove any remaining color. A final wipe with your rag to remove any left over oil completes the process.
Since Walnut Oil is slow drying, the same method can be used at the end of the day. If the brushes are to be put aside for a week or more, a final washing in mild soap and water is recommended.
The simplest approach to solvent free painting is to execute the painting directly in one application, thinning the color only with a small quantity of Walnut Oil or Walnut Alkyd. Use only the smallest amount needed and apply the color directly to the surface of the canvas. For the greatest permanence, the colors should be applied thinly. When multiple layers of color are required, the technique is quite simple if a few rules are remembered.
-Paint Thinly…Heavy applications of color are too massive (ultimately brittle) to age well. Such applications are generally liable to wrinkle or cause cracking. It is a good idea to apply color in such a fashion as to assure that the canvas texture is not lost.
-Fat Over Lean…this is the same thing as flexible over inflexible. The first coat of color should have little or no medium. Each successive layer should have slightly more oil or medium added to it than the underlying coat. This has little to do with the oil content of the color-simply add more medium to each layer of color.
-Thick Over Thin…Thicker or heavier layers of color need to be applied over thinner layers of color. Often when thin layers of color are applied over thicker layers, cracking can occur-this is especially true for whites composed with Titanium or Zinc when they form the underlying structure. (Titanium and Zinc Whites act as though they have high oil content and they must be used carefully in underlying applications. They are generally not recommended for use in underpainting unless applied very thinly on a porous ground and allowed to dry thoroughly and hard. Zinc white is especially sensitive in this regard.)
Note: Glazes applied with appreciable quantities of medium in exceptionally thin layers are an exception to this rule.
-Slow Over Fast…Slow drying colors such as Titanium White, Cadmium Red, etc. should be applied over faster drying colors such as Burnt Umber to avoid cracking. In addition, sufficient time should be allowed for the underlying layer to dry thoroughly.
-Use a sufficiently porous ground with “tooth”…Oil colors adhere by mechanical adhesion. This requires a ground coat that the oil can sink into and some surface irregularity to grab onto. Linen or cotton canvas prepared with a first quality acrylic gesso fulfills this requirement nicely. Remember that gesso, like your color, needs to be applied thinly and the more one preserves the texture of the canvas weave, the better the adhesion of the color.
-Use the same medium throughout the painting…This will help to avoid difficulties in the painting structure that can lead to cracking due to uneven drying rates.
Solvents have been used effectively in Artists Materials from the 19th century onward. Appropriate use of solvent combined with oils and resins produced mediums that often overcame the technical constraints of painting in oil.
However, solvents are highly toxic and, when used extensively, very detrimental to the appearance and permanence of the work. Furthermore, it appears that artists of the European Renaissance did not use solvents to thin their color, but preferred to paint directly, using the oil in the which the color was ground as their medium…”When they are ground with these oils (Walnut or Linseed) which is their medium, nothing else is needed so far as the colors are concerned, but to lay them on with a brush” Vasari on Technique, Georgio Vasari, 1550 (Available form Dover Books as a reprint). The fine condition of works from this period attests to the correctness of this approach.
Solvents are neither necessary nor desirable when working with oil colors. The oil in which the color is ground with perhaps the addition of a fast drying, solvent free, alkyd resin and a few simple techniques enable the artist to paint with traditional oils completely free from harmful solvents.