These processing and embedding cassettes are fitted with a plastic lid attached by a unique hinge enabling quick attachment and removal. They are precision moulded from a solvent and acid resistant plastic, an advantage for decalcification of specimens. The three- sided textured writing surface and flat front provide an advantage when writing and make the cassette particularly suitable for use with cassette printing machines. Moulded with parallel vents for enhanced fluid and wax transfer, this cassette has thickened walls for