underpainting white?

[incolorinred]

hey,

I have a few questions about underpainting with oil paints.

I have seen paints out there called "underpainting white"... are these actually used in underpainting? and how are they different than other white paints?

Please share your experiences and practices with underpainting.

[dbclemons]

Yes, for underpainting; although, it may be used throughout the painting layers if you want, and for tinting. It's mixed with linseed rather than the more common safflower oil. Winsor & Newton's is titanium pigment. They also make a Foundation white which is lead and linseed oil. Safflower oil is not recommended for initial layers since it dries more slowly and isn't as strong as linseed.

[arttorney]

Please share your experiences and practices with underpainting.
If you're a glazer then a smart practice dating back to the renaissance is to underpaint with complementaries, such as a corroded copper green under the flesh tones. It shows through a bit and gives the upper layers a richness or glow. Having the upper colors diluted with a more transparent white helps preserve this effect and so really opaque white is not so good in the top layers.

I tend to paint in impasto, and so I use drybrush or scumbling to achieve effects others might do with a glaze. If you are like me, then the texture of the underpainting is probably more important than the color. If I make the texture of a blocked out area be a series of sinuous brush squiggles, then when the underlayer is touch dry I can drybrush another color across the top. Those squiggles will take on the color of the new layer because of the paint catching on one side of the little ridges. With a little practice and advance planning you can make some really bizarre looking little hatch marks and things like that which would drive you buggy if you tried to paint them directly.

Because of the way the oil paint expands and contracts as it dries, you have to do the dry brushing about ten days to two weeks after the lower layer for best results. If you are a glazer you have to go "fat over lean." That means that you dilute the lower layers with solvent so the underpainted layers have less oil in them per unit volume than the layers above. That way the layers above will be a bit more pliable and less likely to crack during drying. These guys went into underpainting in great detail: http://www.conceptart.org/forums/showthread.php?t=64674