Paper on which design has been printed in a certain way that permits precise transfer to another surface. Decal is often done by wetting the paper and applying it face down. The printed motif then attaches itself to the new surface whilst releasing itself from its original backing.
The technique is somewhat similar to dry transfer lettering or decorative prints being applied to tiles and ceramics. The practice is now commonplace for reproducing artwork faithfully and consistently on ceramics such as these plates reproducing art from the Milanese artist Piero Fornasetti (1913-1988). The Danish artist Bjørn Wiinblad (1918-2006) Featured below, has been reproduced on porcelain by Rosenthal GmbH and the result has since become valuable collectibles.

Image attribution Sabine Schrenk (Rosenthal)