TIPS & INFO for oil painters
- Lo-Fat Diet
(principle of "fat over lean" plus data on
oil content, drying rates,
and dry paint film characteristics)
Oil painters frequently build a painting in layers. In layering paint, the artist must be concerned with the relative flexibility of the paint layers, along with the amount of binder in the paint and its drying rate. To ignore these factors is to invite all sorts of problems.
Three rules of good technical practice are:
note about the charts
Ratings are based on high quality paints made from superior grade pigments and with a minimum of or free of adulterants. In order to obtain consistent drying rates and a consistent, buttery texture, many modern manufacturers - particularly makers of lesser quality paints - add dryers, retarders, and other modifiers to their paints, which may not therefore conform exactly to the specifications laid out in these charts. For accurate information about the particular brand(s) of paints you use, contact the manufacturer(s) directly.
build muscle, stay supple
Try coating a sheet of rubber with gouache paint, bend the sheet, and then see what happens. The paint will crack and flake off. This is exactly what happens when rigid paint is layered over more flexible paint.
Some artist's colors produce a tough, leathery, and flexible veneer. Others produce a hard, brittle finish. Still others fall somewhere between. Layering less flexible paint over more flexible paint should be avoided, and it is better that strong, tough paint overlies more fragile paint.
paint film characteristics*
Flexibility: F=flexible; E=fairly elastic; P=partially brittle; B=brittle
Strength: T=tough/strong; H=hard; M=moderately hard; S=Soft
Chromium Oxide Green
Green Earth (Terre Verte)
Lead White (Flake, Cremnitz)
Lemon Yellow (Strontium)
Naples Yellow (genuine)
Ultramarine Blue, French
quick weight loss
Drying rates are of much greater concern to oil painters than to those who use other media. Oil paintings take an extraordinary amount of time to dry completely. Even after a picture is dry-to-the-touch, the process continues and chemical action persists for many years, and even centuries.
The painting above at left is severely cracked, most likely because slower drying paint was layered under faster drying paint. When the surface of a lake or pond dries up while the mud underneath remains moist and malleable, the same kind of cracking occurs that is seen in the photo on the right.
It is vital that the upper layer of paint not dry more swiftly than that beneath it. Consider a muddy pond during a drought. The mud on top, directly exposed to sun and air, dries quickly, while the protected mud underneath remains moist for a long time. The moist mud continues to move around as it dries. Dry dirt on top that is hard and rigid cracks under the stress. This is exactly what happens to an oil painting when the paint on top is faster drying than the paint on the bottom.
Burnt Green Earth
Chrome Green, Yellow
Cadmium Green, Orange, Red, Yellow
Chromium Oxide Green
Cadmium-Barium Red, Yellow
Cobalt Blue, Green, Violet, Yellow
Indian (Diarylide) Yellow
Green Earth (Terre Verte)
Umbers (Raw, Burnt)
Naples Yellow (genuine)
Lemon Yellow (Strontium)
Lead White (Cremnitz, pure Flake)
Mars colors (Yellow, Red, Violet, Brown, Black)
Madder Lake (natural Alizarin)
Transparent Oxide Red, Yellow
Umbers (Raw, Burnt)
Ultramarine Blue (French)
Transparent Yellow Ochre (Transparent Gold Ochre)
Ultramarine Violet, Red
Practically every art student has heard the admonition, "paint fat over lean." This refers to the good practice of layering paint with more binding power on top of paint with equal or less binding power.
Some pigments require more binder, or oil, to make them into paint than other pigments. The artist him- or her-self may also add oil to the paint while painting.
When paint of low oil content is laid over paint with a high oil content, the upper layer adheres poorly and may even be repelled. Oil in upper layers wants to sink down into the lower layers where it is absorbed. When it is unable to do this because the lower layer is already highly saturated with oil, the upper layer floats; the chemical bond that should develop between the two layers doesnt form. Consequently, paint layers separate, paint chips and flakes off, and fissures develop.
Many artist's pigments have been tested for their oil indexes (the amount of oil needed to grind a pigment into a paste of average consistency). Those with a high index typically contain much oil, and those with a low index have less. The numbers in the chart that follows are the oil indexes for specific pigments.
54 Venetian Red
76 Yellow Ochre
92 Cadmium Orange
56 Flake White
76 Cadmium-barium Yellow
96 Prussian Blue
63 Spanish Red
79 Cadmium-barium red
97 Cad.-barium Orange
64 Chromium Oxide
82 Naples Yellow
100 Alizarin Crimson
65 Cobalt Green
83 Indian Red
101 Ivory Black
66 Cobalt Violet
83 Mars Violet
103 Raw Umber
71 Zinc White
85 Fr. Ultramarine Blue
112 Cerulean Blue
72 Zinc Yellow
87 Titanium White
118 Raw Sienna
73 Phthalo Blue
119 Mars Yellow
128 Mars Black
129 Burnt Sienna
136 Burnt Umber
144 Green Earth
eat some fat, eat some lean
It is easy to become confused by all the information that has been provided. What is to be done, for example, when a color is brittle (it should normally be used in the underlayer), flexible (appropriate for the overlayer), and has a moderate oil content (belongs in the middle layer)? Obviously, a color with those attributes cannot be easily assigned a logical location in the strata of a painting. There may also be situations in which a specific color is needed for the task at hand and no other color will do, but it is not appropriate for the layer of paint it will be consigned to.
There are several potential solutions in such situations. Most are, necessarily, compromises.
First look for an alternate color that is similar to the one you want to use but which possesses more suitable attributes. If, for instance, a clean and brilliant violet is needed, choose rapidly drying manganese blue for the first layers of the picture, and slowly drying ultramarine blue for the later stages.
When there is no viable alternative color, avoid using the questionable color as it comes straight from the tube. Instead, mix it with another color that has opposite characteristics. French ultramarine blue, for example, dries too slowly to be used straight in the first layers of a painting, so it needs to be combined with a rapid drier. Umbers are very good for this purpose. On the other hand, umbers are notoriously high in oil content. To use them safely in the starting layers of a picture, they need to be modified by paints with little oil, such as chromium oxide green or venetian red, both of which are average driers containing a minimum of oil.
Unfortunately, there will occasionally be circumstances when mixing colors together is not a practical solution. There may be aesthetic considerations that require the use of a technically inappropriate color as it comes straight from the tube. In such cases, the pictorial, rather than the technical demands of the painting should win.
* Information from which the charts were compiled came from several paint manufacturers and from the following two very useful books: The Artist's Handbook of Materials and Techniques by Ralph Mayer, and Reed Kay's The Painters Companion.
- Painting Medium:
make your own
and cut costs
- Varnishes: easy to
purpose and types
- Painting Oils : use and
- Other Painting Fluids:
balsams & driers
- Free palette cups
- Recycling paint thinner
There are several good reasons for preparing your own painting mediums, and even varnishes. First, there is the cost. You can easily make it yourself for a small fraction of the price of a manufactured product. Second, there is the question of what is in a commercial medium; inferior ingredients are often used, along with undesirable modifiers. Finally, once you become devoted to a particular brand there is always the possibility that the formula will be "improved," with the result that performance characteristics change. Since manufacturers’ recipes are proprietary, there is no way to find out what was in your favorite product in order to attempt to duplicate it.
For greatest economy, obtain ingredients in the largest sizes available. Also look for sales.
In a clean jar, simply combine the ingredients as listed in a recipe below. Gently agitate the jar until the contents are thoroughly mixed, and then let it sit until any air bubbles have disappeared.
Characteristics of a recipe can be adjusted by slightly changing the proportions of the ingredients or by altering the ingredients (such as by substituting walnut oil for refined linseed oil). Each ingredient has its own properties and effects, which are reviewed in the sections that follow this article. Begin with the recipe as stated, and then experiment until you arrive at what you want.
basic, thin-bodied painting medium that dries slowly
2 parts refined linseed oil with 1 to 2 parts odorless paint thinner or gum turpentine
solution with average body that dries at a moderate rate
1 part refined linseed oil, 1 part stand linseed oil, and 2 parts odorless paint thinner or gum turpentine
student stand-oil medium
dries faster than Student Combination and is slightly more viscous
2 parts stand oil with 1 to 2 parts odorless paint thinner or gum turpentine
used for both painting and glazing, it dries relatively rapidly
1 part stand linseed oil, 1 part dammar varnish, and 5 parts gum turpentine
thicker than the All Purpose medium above
1 part each stand oil and dammar varnish with 2 parts gum turpentine
dries swiftly to a hard, smooth surface
9 parts dammar varnish, 9 parts gum turpentine, 4 parts stand oil, and 2 parts Venice turpentine
adds body to paint while improving drying rate
Equal parts dammar varnish, linseed oil, and gum turpentine
dries swiftly to a hard, smooth surface
4 parts each of dammar varnish and gum turpentine, plus 2 parts sun-thickened oil and 1 part Venice turpentine
dries very rapidly
3 parts stand oil, 3 parts gum turpentine, 2 parts dammar varnish
fast drying and highly viscous
1 or 2 parts stand oil, plus 1 part dammar varnish (note that the varnish contains gum turpentine)
alternative for those with alergies to paint thinner or turpentine; medium to heavy bodied, dries at slow to moderate rate
1 part stand oil with up to 2 parts refined linseed oil (the refined oil offsets the high viscosity of the stand oil)
WHAT VARNISH DOES
There are three types of varnishes an artist might use: straight varnish as an ingredient in glazing medium, picture varnish, and retouch varnish. The material in widest use is dammar, and that is the only varnish discussed here.
Shown is commercially prepared 5-pound cut dammar varnish.
as an ingredient in painting medium
In a glazing medium, varnish increases the translucency of colors, adds a slight gloss to the picture, and levels (smoothes) the painting’s surface. In addition, upon drying it has the benefit of increasing the hardness of the dried paint film and increases the speed with which the paint dries. When glazing in layers, this means a shorter wait until a fresh layer of paint can be applied.
Picture varnish provides a permanent protective coating for a finished painting.
Picture varnish contains a higher percentage of turpentine than straight varnish. It is applied to a painting that is sufficiently dry, usually 6 to 12 months after completion. The coating protects the painting from scratches and accumulated dust and grit. Since it is highly water resistant, varnish isolates the painting’s surface from airborne moisture. The glossy sheen that varnishing produces adds to the richness of the painting’s color and evens out its appearance, eliminating “sunken in” or matte areas.
Retouch varnish is a dilute form of picture varnish that serves a variety of purposes.
Retouch varnish restores a wet appearance to a dry, in-progress painting before work resumes. This makes it easier to match fresh colors to the colors of the picture. It is also useful in glazing techniques to prevent the dry under-layer from being disturbed when a new layer is spread on top, and to allow an unsatisfactory layer of fresh paint to be wiped away with painting oil without damage to the original under-layer.
The standard is “5-pound cut,” or 5-pounds of dammar crystals dissolved in one-gallon of turpentine, although other proportions are used as well.
Dammar crystals in raw form are dissolved in gum turpentine to make varnish.
To make about a pint, follow the proportions cited below to obtain the consistency you prefer. Wrap the crystals in cheesecloth, tying the cloth shut with string. Immerse the sack in a jar of gum turpentine; do not use odorless paint thinner, which will not dissolve the crystals. Cover the jar and let stand until the crystals dissolve, and then remove the cheesecloth.
Dammar crystals wrapped in a cheesecloth bag and immersed in turpentine to make varnish.
In 10 fluid ounces of gum turpentine, dissolve the following dry weights of dammar crystals:
Combine 4 parts prepared 5-pound cut dammar varnish (the type typically sold in liquid form by art supply shops) with 1 pint gum turpentine.
To 5 ounces of 5-pound cut dammar varnish (the type typically sold in liquid form by art supply shops), add 13 ounces of gum turpentine.
A solvent is a substance that disolves other materials. For instance, solvents typically used by oil painters disolve the binding oil in paints, making a solvent very useful for rinsing brushes and cleaning tools. In a painting medium, solvent helps make the paint more creamy or fluid. Since it disolves the oil in the paint, however, artists rarely dilute paint with solvent alone; it is normally just one ingredient of several in a painting medium.
TYPES OF SOLVENTS
For artistic use, gum spirits of turpentine in either “rectified” or “pure” form are considered best; avoid wood turpentine with its strong and highly offensive odor. In painting medium, solvent makes the solution more liquid or less viscous. It evaporates at a moderate rate and has no effect on the drying speed of paint. Turpentine leaves a slight gummy residue upon drying (less than 1% by volume). As an ingredient in painting medium, the residue is of no consequence.
Artist's grade turpentine is labeled as "gum," "spirits," or "gum spirits" and may be designated as "pure," "rectified," or "distilled."
odorless paint thinner
“Odorless Paint Thinner” or “Turpentine Substitute” is a petroleum product. It performs in the same manner and is used for the same purposes as turpentine, but is a bit more watery and leaves no gummy residue. “Odorless Mineral Spirits,” sold by house paint retailers, is not as well purified as odorless paint thinner or turpentine substitute, and it emits a more pronounced aroma.
Odorless turpentine or turpentine substitute is the a solvent used in oil painting.
Resins like dammar do not readily dissolve in odorless paint thinner, so it cannot be used to make varnish. In a glazing medium, only a small proportion of prepared varnish added slowly will dissolve in paint thinner. As a result, recipes that call for varnish generally have to be adjusted when using odorless paint thinner in place of turpentine.
Several vegetable oils are used by painters. All serve essentially the same purposes.
As a painting is built up in layers, the good practice of painting “fat over lean” should be adhered to, which means a little extra oil should be added to each subsequent layer of paint. This is one important function of a painting medium.
In glazing, increasing the amount of oil in the paint is critical. Oil in tube paint acts as a binder; it holds pigment particles together as a buttery paste and holds the paste to the canvas. When spread out into the extremely thin veneers that are typical in glazing, there is not enough oil in the paint to effectively do its job. Thus, the amount of oil must be increased with the help of a glazing medium.
Oil also compensates for the tendency towards brittleness of resins like dammar varnish, which are normally present in glazing mediums. Oil reinforces the elasticity of the dry paint film, making it more durable. In addition, since varnish is easily dissolved by solvents, the oil helps in resisting the solvents’ effects.
TYPES OF OILS
refined linseed oil
A thin-bodied oil, refined linseed dries more slowly and yellows more severely than other oils.
stand linseed oil
Stand oil is preferred over others by many painters. It dries relatively swiftly, yellows little, and forms a tough elastic film. This is a heavy-bodied oil, being quite viscous like molasses.
Even more viscous than stand oil, sun-thickened yellows less and dries a bit more quickly. Otherwise, the two share the same characteristics.
Walnut oil is about the same consistency as refined linseed but yellows minimally. In other respects, it performs in the same way as refined linseed, although some authorities claim it is more likely to cause cracking with age.
Both poppy (left, below) and safflower oil (right) are very thin-bodied and transparent, like water. Because they yellow less than other oils, they are often chosen for use with pale colors. Poppy-seed oil is sometimes used as a drier since it sets so rapidly, unfortunately it is more likely to cause cracking than other oils.
MORE PAINTING FLUIDS
You can paint with just oil, or one can use a medium that consists of oil plus solvent and/or varnish. Those are the basic ingredients in most painting mediums. Some artists may also use a balsam like venice turpentine, or add a drier or even bee's wax to their painting medium to elicit certain qualities.
Venice Turpentine is not actually turpentine; it is an oleoresin (oily resin). An extremely thick material, it is included in some glazing mediums for its glossiness and pronounced leveling quality: it causes the paint to even out into a very smooth, glass-like, and hard surface.
A drier does exactly what its name implies: it accelerates the drying of paint. As noted above, poppy-seed oil is sometimes used like a drier. In linseed- and walnut oil-based painting mediums, however, cobalt drier is the more usual choice. A drier should be included in a painting medium only in a very small amount, lest it produce cracking.
Keep Your Lid On
If you’ve taken one of my oil painting classes, you’ve heard me explain how to recycle soiled paint thinner so it can be re-used (in case you missed the explanation, it’s repeated below). In addition to saving a ton of money on paint thinner, there is a side benefit: all those jar lids. They make excellent palette cups, as well as handy vessels for storing mixed paints.
To use as a palette cup, just pour a small amount of painting or glazing medium into the lid. When the medium has become too soiled or too old to continue using it, just toss the lid away and grab another from your stockpile.
For storing left over oil paint, transfer the paint into a lid, cover it tightly with plastic wrap and place it in your kitchen freezer. The paint can be kept viable for quite a long time this way.
You can save a ton of money by reusing paint thinner instead of disposing of it at the end of each painting session.
To recycle paint thinner, begin by filling a large jar about half full with thinner to use for rinsing brushes and for painting. When it gets too dirty to continue using, set the jar aside for several days. All the debris, paint particles, and oil will settle to the bottom as sludge. Pour the now clean paint thinner into a fresh jar, leaving the sludge behind. Dispose of the first jar…but keep the lid.
- How much painting
medium should I use
- What is "cloak" painting
medium? The painting is
still tacky after several
weeks; should I use Japan
- Found out it's "copal"
medium; is retouch
varnish okay for hiding
- How do water-mixable
oil paints compare to
traditional oil colors?
I took a painting class with you recently. You talked about glazing and did a demonstration. In your talk you said only a little glazing medium is needed, but during the demo I saw how you mixed a lot of medium into the paint. Why the contradiction?
------- Jenny Nolan
This is a case of, “Do what I say, not what I do.”
Less experienced students tend to overuse glazing medium, often reducing the paint to a watery consistency, so I generally caution them to keep the use of glazing medium to a minimum. To better understand the glazing process and use of medium, read the following.
going on a diet
A fundamental technical rule in oil painting is to “paint fat over lean.” This means that less oily paint should never be applied on top of oilier paint. If you defy this rule, upper layers may not properly adhere and might eventually peel off the picture (delaminate). Thus, the first glaze layer should contain the least amount of oil, the next a bit more, and the final layers the most oil.
Painters accommodate the fat-over-lean rule in several ways.
The most technically sound approach is to choose the colors used in each layer thoughtfully. To make dry pigment into paint the pigment is ground together with oil. Each pigment, or color, requires an optimal amount of oil for it to become paint; some require more oil, others less (called the oil absorption index). For the initial layers of a painting, select colors with a low index; for the middle layers opt for colors with a moderate index; and the colors in the upper layers should have a high oil absorption index. (The oil absorption indexes for some commonly used artist’s colors are given in the chart that appears in the Archives of this web site. Select “Archives” from the menu above, “Oil Painting” from the resulting sub-menu, and then scroll down to the “Fat-Free Foods” heading.)
The first step in converting dry pigment into paint is to grind a little oil into it. As the process continues, more oil is added until the optimum amount is reached, transforming powdery pigment into a buttery paste.
It is not always possible to layer colors in this manner, however. It is not unusual for a specific color, one that is low in oil, to be needed for a final glaze layer. In such cases the amount of oil in the paint must be boosted. This is often done by adding an oily glazing medium to the paint. As layers of paint are built up, paint is made oilier by increasing the amount of medium in it. (Adding medium also has the benefit of making the paint more translucent.)
Another method is to have several different glazing mediums on hand. Some painters have a “lean” medium for the first layers; this contains proportionally less oil than the artist’s other recipes. A “moderate” glaze medium has a higher oil content than the “lean,” and a “fat” medium has the highest proportion of oil. As the painting develops, the artist switches from the “lean” medium to the “moderate” one, and then finishes with the “fat” glaze medium.
A thin, medium, and fat glazing medium are prepared to help adhere to the fat-over-lean rule as development of the painting progresses.
These various approaches are applied individually or in combination with one another as circumstances dictate.
Most of the transparent artist’s colors typically used for glazes already contain an adequate amount of oil exactly as they come from the tube. Nonetheless, you may find that adding a small amount of medium improves your ability to manipulate the paint.
The key to using a glazing medium is to exercise restraint. If you use too much too soon you are left with nowhere to go; you will have reached the maximum amount of oil possible in the paint before you have gotten to the final layers of the picture.
At its extreme, a glaze color is brought to a syrupy consistency, but never watery. If you go beyond a syrupy consistency you will lose control of the paint – it will go where it wants to go rather than where you want it to.
Remember, spreading paint into a thin, transparent layer is achieved through manipulation of the paint, not by turning the paint into water.
Question Part-1 (Driers):
Do you have experience working with cloak painting medium? I have worked with it often but am having difficulty with one painting remaining still sticky and tacky after six weeks. Do you have any suggestions for me? Perhaps a Japanese dryer on top?
----- Erin McGee Ferrell
Answer Part-1 (Driers):
Before I get on to the issue of your painting medium, I must state in the strongest possible terms, do not apply a drier on top of your picture!
Driers are not intended to be used that way and will do nothing to make your painting dry faster. A more likely outcome is a horrible mess and plenty of surface cracking. Experienced painters sometimes add a tiny amount of drier to a painting medium in order to accelerate the drying of the paint it is mixed with. But driers are known to cause defects in paintings even when used properly with knowledge and care. More on this topic appears below, but for now let’s discuss why your painting may have remained tacky.
I am not familiar with "cloak" painting medium. Is that a brand or a type of medium? Can you tell me anything else about it?
Since you have worked with this medium before with (I assume) some success, the following question comes to mind: why there are difficulties with one particular painting?
Although the medium you are using may be the same type as before, is it the same brand and, if so, is it from the same jar or batch? Companies often “improve” their products with new formulations. It is also possible that that the particular container of medium you are using has become contaminated in some way (moisture trapped in the container could conceivably alter the medium’s performance characteristics).
One specific possibility that occurs to me is that the underlayer of paint may not have been sufficiently dry before working on top of it, or that a very slow drying color was used in an under-layer which might affect the drying speed of new layers of paint.
Question Part-2 (Driers):
Thanks for the info. The medium is copal. I believe that I put it on too soon. I have checked with the manufacturer and am lightly applying a retouch varnish spray to mask some of the stickiness yet allow some breathability. Not that this is the best solution but the installation has an inflexible contract date.
----- Erin McGee Ferrell
Answer Part-2 (Driers):
I am glad to hear you have found a potential solution, although I am not certain that I am in agreement with it.
It seems to me that applying varnish to a picture that is still tacky will impede drying while adding unnecessary complexity to the paint film. Keep in mind that, although retouch varnish dries rapidly and may (imperfectly) mask the fact that the painting is sticky, the paint beneath will still not be fully dry. As it continues to dry, the paint remains soft and malleable, moving about under the varnish like wet mud beneath the hardened dirt surface of a drying puddle. Like the top-coat of dried earth, the coating of varnish will most likely crack severely.
Following is some information about copal that you should take into consideration.
Copal is a type of varnish but the term is rather vague, since it is applied to more than a dozen different resins, some available in as many as ten grades. Consequently, it is difficult to know exactly what one is getting when purchasing copal varnish or a painting medium that contains the varnish. Copal is a comparatively hard resin. A varnish made with it frequently also contains rosin, linseed or tung oil, and a lead or manganese drier.
The use of products like copal painting medium has widened in recent years. The term "copal" is vague so there is uncertainty about the ingredients and quality of such products.
The best grades of copal crystals are expensive and are rarely found in artists’ varnishes. Even when of the finest sort, copal is considered to be impermanent since it darkens with age and paintings made with it are likely to crack. If rosin is present in the varnish, it merely serves to reinforce these defects since rosin also darkens and cracks, and driers are to be avoided since they introduce their own failings – which are many.
Copal resin crystals are obtained from more than a dozen species of trees from many parts of the world, with some types being available in as many as ten different grades.
If you wish to use a resinous medium for your paintings, I recommend mixing up your own using the more reliable dammar.
When time is of the essence, there are methods for accelerating the drying of an oil painting.
Rosin is frequently an ingredient in copal painting mediums. It is a hard substance that dissolves easily in solvents commonly used by painters. In addition to this deficiency, rosin contributes to weak paint films that are prone to darkening and cracking.
The least desirable, but sometimes the only viable option, is to add a few drops of drier (such as cobalt, manganese, or Japan) to your painting medium. In most cases, the painting should be touch-dry in 24 hours or less. Driers, however, are known to shorten the life of a picture, and may cause it to crack. A drier should be used only in a small amount; overdoing it can create a host of problems. It should never be used in thick paintings or in an underpainting. The main value of a drier is in glazing, when it is easy to grow impatient as you wait for each glaze layer to dry before applying the next.
Cobalt drier is one of several similar products. All driers must be used sparingly and expertly to avoid serious defects in the paint film. The least damaging type of cobalt drier is cobalt linoleate. Other commonly used driers are manganese and Japan.
Being aware of their many shortcomings, I personally avoid driers and have used them in only a few extreme situations. A more technically sound practice is to select faster drying colors if time is an issue, and use a painting medium that contains a fast-drying oil like sun-thickened linseed, along with a reliable resin such as dammar. Another alternative is an alkyd-based painting medium rather than one made with oil; alkyd materials dry rather speedily. Ideally, you should also allow adequate time for the paint to dry sufficiently between layers.
Another way of controlling the drying time of a picture is to use faster drying colors. Umbers, for instance, are referred to as “siccatives” because they dry so rapidly.
For information about the characteristics of many pigments, refer to the following two pages on this site:
In addition, below is a list of colors ranked for their drying rates. Slower drying colors should be avoided in underlayers, and be reserved for later stages in a picture’s development. The information is mostly from the fourth edition of Ralph Mayer’s The Artist’s Handbook of Materials and Techniques.
umbers, Prussian blue, lead white, Phthalocyanine blue, cobalt yellow, burnt sienna.
raw sienna; cobalt colors; black, yellow, and some red iron oxides; chromium oxide; viridian; Naples yellow (genuine); zinc, strontium, and barium yellows (often labeled as lemon yellows).
titanium white, green earth (terra verte), cerulean blue, French ultramarine blue, yellow ochre, alizarin crimson.
very slow driers
ivory black, cadmium pigments, vermilion (genuine), zinc white, carbon black.
Question (Water Mixable Oil Paints):
I was in Michael's [Arts & Crafts store] today and saw "water mixable oils" (Winsor & Newton Artisan). Wondering if you ever use this medium? How is it as far as coverage, workability and color comparison to regular oil paint?
----- JoAnn Fleming
(Water Mixable Oil Paints):
Several companies offer water-mixable oil paints, Winsor & Newton among them. Other brands are Grumbacher MAX and Holbein Duo Aqua. Ratings and price ranges are provided on the Material Advice page of this web site.
Water-mixable paints need not be used with traditional solvents of odorless paint thinner or turpentine, which many individuals are sensitive or allergic to. They may, instead, be thinned with ordinary tap water. The binder in these paints is linseed oil, the same as with old-fashioned paints, except that the oil has been chemically altered to allow the paint to be mixed with water. There are also special painting oils and mediums made for use with water-mixable oil paint.
The same materials used with traditional oil paints – turpentine, linseed oil, dammar varnish, and so on – may be used with water-mixable oil paints instead. However, once this is done, the paint can no longer be used with water.
My own experience with these paints has, frankly, been disappointing. Although they are advertised as performing in the same way as regular oil paints, I have found that they sort-of-do-but-don’t-really. When used with water, the paints have a tendency to begin drying rather rapidly, making blending and wet-in-wet techniques difficult to carry out. Combined with a painting medium made for them, water-mixable paints perform a little better, but not a lot better. These are not professional grade paints. They are student quality and consequently have only modest tinting (coloring) strength.
In spite of these draw-backs, for the individual who prefers or must avoid traditional solvents, they offer a reasonable alternative to ordinary oil paints. With practice and experience, they can be made to perform satisfactorily.
My advice to anybody using water-mixable paints is to not think of them as being oil paints at all. Consider them as an entirely different medium, and learn to master their strengths and weaknesses, just as one would do with acrylic paints, egg tempera, or watercolor. Every medium has its own character, and water-mixable oils are no different in this respect.
A Reader Responds
You state that all water-soluble oils are student grade but that isn't true. Well, it's not true for all brands of WSOs.
Holbein Aqua Duo and Royal Talens Cobra are both professional grade. Others list Weber "W" oil as professional grade too but I haven't confirmed that. W&N Artisan and Grumbacher MAX are intermediate grades. LUKAS Berlin is a student grade. Grumbacher MAX2 and Royal Talens Van Gogh H2Oils were both student grade as well but have been discontinued in favor of the higher quality lines presently offered by their respective companies.
If you visit the websites and contact the companies they will fill you in on the specifics (pigment load, lightfastness, etc.).
Just an FYI.
----- Jeffrey Phillips
The Author Replies
Thank you for taking the time to write, Jeff, and for your educated comments.
It appears that you have done some research, and you are indeed correct that not all water-soluble oils are student grade. I tend to lump paints into two broad categories: professional and everything-else, which I simply describe as being student grade (perhaps this is a practice I should discontinue). Nonetheless, as you note, there are water-soluble paint brands that fall somewhere in-between, as do Artisan and MAX. Also, as you state, Aqua Duo is indeed considered a professional paint and my article is in error in this respect.
Still, I must stand by my statement that all brands of water-soluble oil paints have provided me with disappointing experiences.
----- Fred Kaplan