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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.
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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.
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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…
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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.
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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
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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.
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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.
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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!
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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.
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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.
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I don’t fix my completed oil pastel paintings for two reasons:
- The nature of the oil pastel medium is to be self-fixing. It is not dusty or loose on the surface – I feel there is simply no need to fix something that is already “fixed” in place.
- Fixative changes the color of the oil pastel. (see color swatch below)
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.
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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.
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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.
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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.
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If you have any question you don’t see answered here, please write to me at OilPastelQuestion@JohnElliot.com
Happy painting! John