Q. While taking a break from soft pastels, I started painting with oil pastels. Whats the difference between oil pastels, oil sticks and oil bars? Do any of these dry enough so I wouldnt have to frame them behind glass?
A. Oil sticks (also known as oil bars, depending on their shape and manufacturer) are made of the same pigments and drying oils used in tube oils. The paint is then combined with wax and rolled into a crayonbasically oil paint in a solid form. This medium, unlike the oil pastel, develops a skin as the oil dries. When this top layer of paint solidifies, it seals the wet paint in underneath, much like oil paint.
Oil pastels are similar to oil sticks, but with one critical difference: The type of oil used in the formulation of oil pastels is nondrying. Because this material contains more wax than oil, it handles much more like a soft pastel, and it will never completely dry. Little to no skin forms on your working surface, and the sticks maintain the same even consistency all the way to the painting surface. Oil pastels are also known to work well with linseed oil and turpentine to create many different and interesting blending effects.
So the material youre referring to may contain small differences in content, but theyre basically combinations of wax (beeswax, paraffin, microcrystalline petroleum wax, or a mixture of two or three), oil and artists grade pigments. There are probably also other ingredients added to modify the handling characteristics of each particular brand, but because this is proprietary information I have no way of knowing what else might be added to each manufacturers version of the material.
Because these materials contain enough oil to make them dry, but also a large amount of other materials that keep them soft and pliable, I have to conclude that their dried surfaces are fairly susceptible to scratching, denting, and other types of physical harm. Its also not recommended that you varnish these media, so its probably best for you to frame any of these paintings behind glass, as you would with a soft pastel.
Drawing Board creator Bill Tilton lives in Raleigh, North Carolina, where hes currently working on a 5×6-foot painting of zebras on the Serengeti Plain.