FOAMCORE
Foamcore
Foamcore, Kappa or Foam board is a very strong, lightweight, and easily cut material used for the mounting of photographic prints, as backing in picture framing, in 3D design, and in painting. It is also in a material category referred to as "Paper-faced Foam Board". It consists of three layers — an inner layer of polystyrene foam clad with outer facing of either a white claycoated paper or brown kraft paper.The above text is a snippet from Wikipedia: Foamcore
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