Here are some frequently asked questions about painting, in particular painting of portraits.
Q: Can I preserve the unmixed colors on my palette so they can be used later?
A: Yes. Lift them from the palette with your palette knife and line them around the edge of a saucer or shallow pan; then immerse in a pan of water. This will prevent skin from forming; when you are ready to paint again, remove saucer from water and stand it on edge to drain thoroughly. (This method might be unwise for important work.)
Q: If I can't finish my painting the first day, does it have to dry thoroughly before I can proceed with it?
A: If you are painting a landscape or still life, continue the painting; if a portrait where you are painting a smooth skin texture, make sure the paint is still wet enough to mix with that which you will apply, or that the painting is dry to the touch. There is a period of the drying when a thin sticky film forms over the paint.
This will either grab and make a bad spot (which can't be blended or wiped), or break the film, causing a rough tear in your smooth paint texture. Before starting to work on a dry painting, brush a very little linseed oil over the areas to be painted. This will also restore flattened-out darks to their true value.
Q: If I decide to paint a face where previously I had painted a dark background, now dry, is it all right to use flesh colors right over the darks?
A: Yes. Just be sure there is not a pattern of heavy lines from brush strokes to destroy the skin texture of the face. If the background is not too rough (because of piled paint) it can be scraped smooth with a palette knife.
Q: Some years ago I hung some recently finished paintings on the wall. Later, when they looked dull, I rubbed linseed oil on them. This improved their appearance so much that I repeated the treatment every year or two. Now I realize that the paintings have become very yellow and dingy. Can they be cleaned, or bleached out by the sun or any other inexpensive and simple means? Can the oil coatings he removed without spoiling the work underneath?
A: I have seen paintings ruined completely by inexperienced persons trying to follow instructions given by someone who has not seen the paintings. Restoring paintings should be done by an expert, and I suggest that you take one of your paintings to such a person at the nearest art museum. Repeated coatings of oil always tend to produce this result.
Q: Can one paint well under artificial light? If so, what is the best kind?
A: Painting under artificial light is never desirable but good results may be obtained by using a four tube fluorescent fixture with two blue and two natural (yellowish tone) tubes. If this makes too much light on your sitter, hang a cardboard shield to block out the light and light the sitter with a bowl reflector using a sixty watt bulb.
Q: What do you think of painting portraits in outdoor settings?
A: I like the outdoor setting so much that I quite frequently find myself sneaking in a background which at least resembles a sky. The play of sunlight is a beautiful thing to paint but care must be taken not to place too much emphasis on the landscape. Otherwise it will not be a portrait but a landscape with figure.
Q: Is it wise ever to portray two or more people in one painting?
A: It is all right to paint more than one person in a portrait. I have found only one objection and that is where two children are painted on one canvas. Each will want the painting later so I usually suggest two pictures as the cost is the same.
There is more to learn about portrait painting, but this is a good start.
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