Next to that, spread a thin, transparent film, called an undertone (swatches 2 and 3). A dark mark on the board behind the film of paint helps to test opacity.The colors in these swatches are ultramarine blue, Venetian Red, and terre verte. The Venetian red is the most opaque of these three.
You can also test the pigment’s tinting strength by adding white. Tinting strength refers to the ability of a pigment to maintain chroma with the addition of white (remaining swatches). Some colors, like pthalo blue are powerful in tints. Some, like terre verte are relatively weak.
Most colors shift a bit in their color temperature. Warm colors typically shift to the cooler or bluer side.
This difference, between opaque pigments and transparent ones, is a very important distinction to make when choosing your paints and laying out your pallet. Opaque pigments are good for blocking in an under-painting with different colors, such as warm vs cool; or for painting out (or over) a passage you wish to eliminate. Transparent pigments are good for sketching in an under-painting like a wash w different values, or for over-painting other colors you wish to alter.
ReplyDeleteWhile you can add white (or a similar opaque color) to a trans. pig. to make it opaque, it is much harder to make an opaque pigment transparent (by adding a glaze medium, but this is a little clumsy).
Another important difference is that you can build up transparent colors (layer over layer) to saturate or deepen it’s chroma, making it richer and darker while maintaining clarity (opaque colors cannot do this, their color value remains constant).
P.S. Thanx for the post on the Abbey murals at the Boston Public Library (Sunday, June 27, 2010). That led me to the Sargent murals and I haven’t gotten anything done since Monday! -RQ
so funny! I was just reading about this in an old art book of mine. It's always nice to freshen up your knowledge. :)
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