Abstract: Imaging material comprising a layer which comprises deformed particulate organic polymeric material such as flattened spheres, which has a memory for its original particulate shape and which is capable of recovering its original particulate shape upon the application of energy above a certain threshold. Examples of suitable particulate material include polystyrene, as it is obtained by emulsion or perl-polymerization in the presence of crosslinking agents, or polyethylene in particulate form, which has been crosslinked by the application of high energy radiation.