The CWC would affect U.S. firms that make dyes and pigments, insecticides, pharmaceuticals, ceramics, nylon, paint and varnish, electronics, textiles, and soap and detergent.

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The purpose was to determine not only what was in the samples in terms of atoms and molecules, but also the precise structures in the interface layer between the original paint and the varnish.

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He painted directly onto this surface, often in acrylics, sometimes brushing on a layer of darkening varnish before the paint cured.

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But atoms from the original paint were also found in the varnish, which may therefore be left in place.

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