Part 11- Underpainting Technique
Pastel Perspectives Part 11-Underpainting Technique
Pastel is a very versatile medium. There are many ways of approaching a picture that will capture interest and provide both opportunities and challenges to you as the painter. Underpainting is one such approach. There are several different underpainting methods. I will first describe underpainting with pastel and water versus pastel and odourless solvent (also called odourless medium). The next part of this series will refer to underpainting with gouache, inks and watercolour.
There are several reasons to underpaint, apart from the desire to try something different. One reason might be that you can’t decide what colour paper to use. Another, and this is my biggie, is when you are using a paper colour you don’t particularly like to work on. In my case this is white or very light toned paper! Some people love it, but my working style, which often involves leaving areas of bare paper showing, means white paper just doesn’t do it for me.
I only blend where I really need to. When using white paper, I find the white speckles showing through annoying, so I will sometimes choose to underpaint. I will also choose to underpaint dark areas like foliage and the like if I am working on a lighter toned paper.
Underpainting with pastel means that your work
is pure pastel as separate from underpainting with other media such as gouache, watercolour, ink or acrylic. Generally speaking, I think it is better to use a waterbased medium for your underpainting. It’s been suggested that oil-based mediums can make your paper brittle, so I usually avoid them. I sometimes use odourless solvent or medium, but using plain water means less additives and a purer work.
Odourless solvent or mediums were developed for those allergic to turpentine. Please be aware that odourless does not mean fume or vapourless. The fumes given off by these mediums, like turps, can be hazardous and should only be used in a well ventilated area. At least when using turps you can smell it, so you’re aware of its presence in the atmosphere.
There isn’t really a great deal of difference between using a product like odourless solvent, and using water in terms of “fixing” the pastel. Both will fix the pastel to a certain extent, allowing you to work over the top in dry pastel with very little transfer of under-colour. I find water is slightly better at fixing and is friendlier to both the environment and the artist.
Pastel is the purest of all the mediums, with very little in the way of chemicals added. It is nice to keep it that way. The difference I find is that odourless solvent produces a flatter underpainting and water a more textured underpainting. Their use is dictated by what you want to achieve. In my experience water gives you better run marks. Water tends to dribble and run down the paper if it is upright on the easel. This is an effect that can be used to your advantage.
Don’t try to underpaint the entire picture. You are essentially giving yourself a base colour in selected areas. Where possible, keep the underpainting to the intended broad abstract shapes of your painting. You may find, depending on the base colour you start with, that you only need to underpaint
one or two areas to make it work for you.
Before you begin your underpainting, make sure your paper will accept wet media. Some of the older style, un-sanded pastel papers will cockle and warp dramatically, making them almost unusable. Start by lightly blocking in the area, or areas, you wish to underpaint, lightly being the operative word. Use too much pastel in the underpainting process, and you will fill up the tooth of your paper. If this occurs, you won’t be able to add subsequent layers of dry colour to your work.
Once you are happy with your roughly blocked in area, take some clean water or odourless medium and a cheap or old paintbrush, dip it in the water/medium and paint over the areas of pastel. I suggest using an old or cheap paintbrush as some of the sanded pastel papers are very hard on your brushes—so don’t use you best sables!
Dispose of any leftover medium as soon as you’ve completed your underpainting, as it will continue to evaporate and you will be inhaling the fumes.
Don’t get over enthusiastic with the wet media. You can have too much, so start with a damp brush first. You can always add more later. If you want the underpainting to run, add a bit more water/medium and tilt the paper, if it isn’t already on an easel. You might prefer to wash your brush frequently if it clogs. It all depends on the effect you hope to achieve.
Don’t be afraid to experiment. Wet pastel isn’t going to behave like your finest watercolours, it can be quite grainy, coarse and even rustic, depending on the brand or the particular pigments, but that is OK.
Allow your underpainting to dry completely then proceed with dry pastel over the top in your usual manner.
Storm Clouds Over Spring Range, pastel on white colourfix paper 20½ x 30 cm (8 x 12") As I said previously I prefer not to work on white paper so here I underpainted most of the subject in broad areas and pasteled over the top. You can see the...
Reflections, Teewah Beach, Sunshine Coast, Queensland, pastel on white Colourfix paper, 30 x 23 cm (12 x 9") Note the run marks can be seen at the bottom of the work where the effect works well as part of the wet sand/reflections.
This picture was painted as a demonstration piece in a workshop. Using white paper, I blocked in the pastel and used extra water to make the wet pastel run. As this picture was done as a demo, there isn’t an image before I wet the pastel underpainting.
Here, a layer or two of pastel has been added over the underpainting, building on the base I had created.