The quality of a oil pastel is a difficult subject. It is mainly a technical issue. Although there are one or two Rules of Thumb that may be helpful.
You would think that the easiest way to figure out if a set of oil pastels was a student grade or an artist grade would be to look at the box. Many boxed sets state right on the box “Artist” grade or quality. The problem with this is there is no industry standard to define what is student and what is artist grade. It is left to each manufacturer. In some companies, this in-house definition is decided by the technical department based on the ingredients and performance of the product. However, in other companies, this is defined by the marketing department. So how do we as artists know what we are paying for and using, and why does it matter?
The most important reason for wanting artist quality is the same in any medium whether its oil, acrylic, colored pencil or pastel. You want the color you put down today to be the same color you see 10 years from now. This ability not to fade is called lightfastness.
A high quality pigment will keep its color better and longer but is more expensive to use in the manufacturing process.
Another factor in the cost of a pigment is the grain size. Finely ground pigment powder blends with other pigment colors easier. But again is more expensive for the manufacturer to buy. So, one way to make a less expensive set of oil pastels is to use less expensive pigment.Once a manufacturer has decided on a pigment and what size grain to pay for, the last cost decision to be made about pigment is how much of the pigment powder to put in each stick of pastel. The quantity of pigment is called the pigment load. The more pigment load in a pastel, the stronger and brighter the color.
The other ingredient that has the most influence on whether the brand is an artist quality is the filler. The least expensive filler that can be used is wax. And the more wax that is used per stick, the less expensive it is to make the stick. A brand made with a large quantity of wax would be considered by most artists to be a student grade brand.
Okay, so now you know some of the technical explanation of what makes a student and an artist grade oil pastel, but how can I tell what it is when I use it? There are no perfect tests that I have found that can help but I have some Rules of Thumb.
Rules of Thumb
- If a manufacturer is known for making quality products in other artist’s mediums, it’s a good bet that their oil pastels have a good quality too.
- If the major online art supply stores offer the brand for sale by the stick, it is usually either an artist quality or a very good student quality brand.
- If the price is very inexpensive, the manufacturer probably cut costs in making the oil pastel.
- Try blending two colors of the same brand together. Do you come up with a consistent blended color?
- Does the pigment extend very far?
The Pigment Extending Test is a way to see how much pigment load is in a stick. If you did this test in watercolor, you would drag the brush until you ran out of water. Then you’d add more water to the brush and see how much further you could drag the color until it faded away. The longer that line you painted before the color disappeared, the more pigment load in that paint. This can also be done in oil pastels. Cover a small area of smooth paper with color from an oil pastel. Push hard with your finger and see how far you can push the color. If an oil pastel can be extended at least a moderate distance, it is easier to mix colors. (Some brand sell an uncolored stick called an extender. This is like adding more water to the watercolor. It allows you to extend the pigment further.)
Left to right: Cray-Pas Specialist, Loew-Cornell, RoseArt, Holbein, Sennelier
As you can see in the above test, the one marked LC for Loew Cornell could not be extended very far. Relative to several of the other brands shown in the above test, this brand was very inexpensive. Doing this test several times, the results on this brand were always poor.
On the RoseArt brand, although the color spread further than the Loew-Cornell, I felt the color was weak and splotchy.
For the other three brands in the test, I found this test to not be helpful. From technical information and what I know about these manufacturers, I consider the Cray-Pas Specialist, Holbein and Sennelier to all be of a similar artist quality. Each had a good consistent color and could be pushed a distance. However, the feel of the sticks kept me from putting down on paper the same amount for each brand so some pushed further than others and I’m not sure that means one is better than the others but that there is another factor at play at this level of product.
There is a commonly believed myth that harder oil pastels are not as good. If the hardness has a waxy feel, this can be true. But otherwise, this is not true. These 3 brands (Cray-Pas, Holbein & Sennelier) have differing ideas on how soft or hard an oil pastel should be. And each brand has loyal users because each artist has an opinion on how hard or soft an oil pastel needs to be to use it in the way that artist wants.
When deciding on which brand of oil pastels to purchase, use the Rules of Thumb described above as a guide. But also consider your personal preferences. Do you like the feel of the stick? Does it mix easily for you? Is it in a price range you are willing to pay?
After considering all of this, you will end up with an oil pastel purchase that is perfect for you.
