Both oil pastel and soft pastel, in an artist quality brand, begin with ground color pigments. The ground pigments are combined with a slight amount of inert oil and wax to create an oil pastel; the ground pigments are combined with filler (often white chalk) and a slight amount of gum tragacanth to make a soft pastel. The soft pastel has a dry feel to the touch, which is why I started calling them “dry pastels” and many artists now use this clarified name. In use, oil pastels adhere firmly to the paper surface whereas dry pastels do not adhere – they are essentially dusted onto the surface, and can thus can be tapped off the surface or brushed off. In a student grade pastel of either type, inexpensive filler material that is dyed with chemical dyes, is usually the component rather than the more expensive colored pigments in an artist quality pastel. Both dyes and ground pigments can sink into the [paper] painting surface, staining to a greater or lesser extent. Colored chalk created for school projects is a different material, essentially chalk or other white or light ground mineral that is mixed with a bit of pigment or dye and usually gum arabic as a binder. Since there is so little pigment or dye involved vs. the chalk itself, school chalk rarely stains a surface and can often be cleaned off completely. Since gum Arabic is water-soluble (it is used in making watercolor paints too), the school chalk will usually wash off with water. When in doubt about an art material, it is best to contact the manufacturer for ‘spec’ information.
An artist quality will have manufacturer lightfast spec sheets and pigment composition available; without this validation of archival quality, you must assume the material is only student grade.
I would suggest you first try Sennelier brand – they are the softest commercially available oil pastel on the market that I am aware of. To make your own would risk that your quality control standards are not sufficient to make archival level oil pastels.
Before doing anything, I always check with the manufacturer of the material that has the oil pastel on it, whether there are substances that can harm the surface. My general process is this: I first gently scrape off any oil pastel on the surface with a single edged razor, plastic ruler, or orange stick. Then I would try an eraser on any remaining pigment. Other options I might resort to, depending on the surface that is stained, are liquid soap, household degreaser, stain remover, etc – but I would always test my surface first. An ultimate chemical cleaner for me has been Weber’s Turpenoid. But if the pigments were staining pigments, nothing it seems will get that faint shadow of color out…
Yes, you can combine oil paints and oil pastels in the same painting. Generally, the paint should go on first. This is because oil pastel never really dries and forever remains somewhat workable – oil paint on top of it would crack and generally be unstable.; whereas the oil paint creates a hard skin and creates a firm base for the oil pastel on top of it. I particularly like to let water-soluble oil paint dry to the tacky stage, and then work oil pastel over it. Remember though that the oil pastel will never dry with a hard skin, so could be damaged if your multimedia work is not framed under glass or plastic.
The exception to the “paint first” rule is when I use oil pastel for the drawing under an oil painting. I use the oil pastel lightly as a sketching medium in this case, preferring it to charcoal or graphite, which can work up into the oil paint and create a dirty effect. When I select compatible colored oil pastels for the under-drawing, if any works up into the paint above, it blends in just fine.
Oil pastel can be layered, usually more layers than soft pastel. Often I warm the oil pastel a bit in my hand before applying it to a cooler layer already on the surface. As far as the realism capability of oil pastel – it is all in the technique. Take a look at my gallery on this web site, or go to www.OPAI.org/web.htm and look over some of the works, especially those artists noted as ‘realists and pets/wildlife painters’ or buy some issues of The Pastel Journal which includes a realistic oil pastelist in each issue since 2002. Colors in oil pastel can be more vibrant that soft pastel or as subtle, again depending on your technique. The main difference between the two is the binder in the stick – oil pastel is essentially a dustfree pastel – and needs to have a firmer hand when applying since dust will not crumble off the stick onto the paper as with a dry pastel, but needs to be applied to the paper with a moderate to firm pressure in oil pastel painting. I would strongly advise looking over my book “Oil Pastel for the Serious Beginner” which is loaded with realistic paintings and the step-by-step information how they were created. The book can be ordered at discount at http://johnelliot.com/book/isbn0823033112/main.htm
The best surface is what works with your style and what you want to express. By experimenting on as many surfaces as possible you will find the best surface for you.
Many oil pastelists use pastel paper, pastelbord, museum board, alpamat, canvas, etc. The choice of surface is covered extensively in my upcoming book "Oil Pastel for the Serious Beginner" published by Watson-Guptill, which you can read about at http://johnelliot.com/book/isbn0823033112/main.htm.
What you have discovered and what you are calling ‘holes' in your oil pastel painting, is an effect much appreciated by many oil pastelists, myself included.
However, if you personally prefer to avoid this effect, then simply make yourself a blender of folded paper towel, and with a gently rotating motion, spread the pastel of your first and possibly second layer, before you continue painting the upper layers.
Additionally, if you select a smoother pastel paper (sometimes I use the smoother ‘back' of a very toothy paper), this can also help. So experiment on different surfaces because your favorite paper for oil pastel painting may turn out to be different from your favorite for dry pastel work.
I’ve used canvas and it works very well with oil pastel. I place a board (like fome-core) behind the canvas if I need to reduce springiness on a stretched canvas.
You can prepare your own grounds by applying a gesso-plus-grit mixture onto a board. The grit can be marble dust or pumice – there are numerous acrylic gesso plus sand, pumice, etc mixtures available on the market or you can mix your own. You should select archival boards, such as museum board, and be sure to paint both sides with the initial coats of gesso so that you don’t get warping…
If you don’t want to use gesso, you can paint with acrylic, and while the top layer is still wet, sprinkle sand, marble dust or pumice over it – tapping off the excess when dry.
For that matter, you can paint with oil pastel directly on archival boards, such as museum board or alpha board, or good quality watercolor paper, and so forth, without applying a special ground. One of the advantages of oil pastel is that it can go on just about anything!
Intrinsically impermanent materials will not be made more permanent with fixative – there is no magic wand that will make degradable materials into archivally permanent materials. Your best strategy is to paint any new paintings with archival professional artist quality materials. As for the painting you have already done, my advice is to carefully frame it, keep it out of strong light and excessive changes of temperature or humidity, and enjoy its beauty before it ultimately degrades.
As long as the oil pastels you use contain INERT oil (such as mineral oil) in the binder, rather than chemically active oil (such as linseed oil), you can paint directly on paper. I have oil pastel paintings I did more than 40 years ago directly on pastel paper, museum board, and 300 and 400 lb watercolor papers. These paintings are just as I painted them, and I expect them to last far into the future.
I do not know the exact formulas used by the major oil pastel manufacturers. However, I have been assured by the Presidents of both HK Holbein and Sennelier, that their professional artist quality oil pastels use INERT oil. Hence, you can safely use these professional quality brands. There may be other brands using inert oil: I will update this site as I learn of them.
Of course, you will need to select archivally safe papers as well – some terms to look for are acid-free, archivally safe, etc.
When in doubt, check directly with the manufacturer.
I don’t fix my completed oil pastel paintings for two reasons:
HK Holbein specifically does NOT recommend the use of fixatives over oil pastel. See their advertisement in Jan-Feb 2002 Pastel Journal page 58.
Sennelier has recently developed a special fixative for oil pastel. I plan to experiment with this for special effects, limiting its use for small areas of underpainting.
I do not varnish my oil pastel paintings for archival reasons. Unlike oil paint, which dries with a hard skin, oil pastel never completely dries but just hardens somewhat over time. To apply a varnish over something that is still workable does not seem prudent as a materials handling strategy. Further, as you may know, an old yellowed varnish layer on an oil painting can be removed by a conservator and a fresh new layer applied because the oil paint has created an impermeable skin in the drying process. I am not aware of any safe way to remove an old yellowed varnish layer from an Oil Pastel painting, since the oil pastel underneath would never dry with a protective skin.
As with fixative, varnish also changes the colors of the oil pastel.
In the following swatch, the left is plain oil pastel, the middle is oil pastel sprayed with fixative, and the right is oil pastel sprayed with varnish.
If used directly from the box, no oil pastels dry the way oil paints or water colors dry. This is because of their unique binder. I should note, though, that when using some special techniques, the oil pastel will dry. That said, however, all oil pastels used as pastels, harden somewhat, but forever remain workable. This is what makes oil pastels different from oil sticks, which are oil paints in stick form and dry with a skin like any other oil paint. Oil sticks are NOT pastels but are oil paints. Oil pastels are a non-dusting PASTEL.
Oil pastels should not be avoided because they are the most durable and least harmful type of PASTEL – this assumes you want to paint in pastel in the first place.
To avoid accidental damage to the surface, it is advisable to frame a finished oil pastel painting under glass or plexiglass. Since the oil pastel by nature is dust-free, you can use plexiglass because loose pastel dust will not migrate to the static-prone plexiglass material. Of course, you must always leave a space between the oil pastel painting and the glass or plexiglass.
All oil pastels can theoretically be used together – but, only professional artists’ quality like Holbein’s medium hard Artists Oil Pastel or the softer Sennelier oil pastel, should be used together. Student grade oil pastels made with fugitive dyes or other non-permanent materials will degrade much faster than the professional brands, and your finished paintings combining these non-professional oil pastels will not hold up well over time.
If you have any question you don’t see answered here, please write to me at OilPastelQuestion@JohnElliot.com
Happy painting! John