2. What technique is described in the following paragraph?
The technique "consists in brushing a transparent layer of paint over another thoroughly dried layer of opaque paint. [...] The two layers of paint are not physically but optically mixed. [This technique] is similar to placing a sheet of colored acetate over a monochrome photograph, [...and] creates a unique "shine through" stained glass effect that is not obtainable by direct mixture of paint".
Source: http://www.essentialvermeer.com
An example of the use of this technique is Vermeer's Girl with the Red Hat (ca. 1665-1667).

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