ARTofficial Intelligence • Cindy Tafil
What’s the difference between turpentine, mineral spirits and turpennoid?
First, all three can cause serious reactions. Turpentine, mineral spirits and turpenoid can cause skin, eye, mucous membrane, and upper respiratory tract complications. Taking out the odor in all three doesn’t mean the danger is gone. It just implies a nasty headache isn’t experienced using these solvents. Turpenoid is an odorless turpentine substitute that is a refined and filtered solvent suitable for oil painting. Odorless mineral spirits does the same thing, but it has impurities. However, if you’re allergic to turpentine, then odorless mineral spirits is probably your only choice. Keep in mind that the expensive turpenoid if not properly used such as dipping the paint brush into a dirty jar of turpenoid will result in an impure application. Keep one jar of solvent on hand for washing brushes (OMS) and the other for actual painting. Always keep the jar with turpenoid for painting as clean as possible.
What exactly is Alla Prima?
It means at the outset, an Italian term for the approach of painting using glazes, scumbles and other techniques. Generally, any painting that is approached loosely is categorized as alla prima painting. Thicker and lighter passages that define the essence of pictorial expression are characterized as alla prima, an opaque application of paint. A scumble is an application of semi-transparent color and a glaze is an application of transparent color.
Flemish painters used all three applications that were completed at one sitting. (wet on wet/alla prima) Contrasts were used extensively with the Dutch masters from thick and thin, opaque and transparent, warm and cool and light and shadow.
Are there dyes in oil and acrylic paints and what are the biggest differences in these mediums?
The answer is yes, but it’s almost impossible to decipher which brands and what pigments are affected. Dyes have been used for inexpensive substitutes for some of the more expensive, intense, and opaque colors of mineral origin; such as the cadmium yellows, reds and oranges. Adding dyes can fortify the intensity of color pigments. The thalo colors are a synthetic green pigment from the group of phthalocyanine dyes that allow a high intensity and bright color used in oil and acrylic based paints.
Acrylic and watercolor paint evaporates, oil paint oxidizes. All paints begin with dry powdered pigments and contain liquid vehicles called binders. Linseed and poppy oil are used as binders for artists’ oil colors. Acrylic paints are made with acrylic polymer (plastic) resins dispersed in water. Watercolor binder is made with a gum arabic solution.
The pigments contain coloring substances of organic or inorganic origin and many of the powdered pigments are synthetic. The permanence of a pigment is determined by its resistance to fading when exposed to direct sunlight.
Neutral colored powders in oil colors, called inert pigments have been colored with organic dyes. These are called “lakes” from the term “lac” a blood red dye from India.
One word of caution: Labels on the tubes of paint do not specify insoluble or non-bleeding pigments or soluble dyes.
“If I create from the heart, nearly everything works; if from the head, almost nothing.”
From the words of March Chagall