Casein formaldehyde

Acronym and details:   milk curds hardened with formaldehyde

Group:   thermoset (but can also be thermoplastic to a certain extent)

Developed:   patented 1899; little used since the 1980s

Trade names:   Lactoid, Erinoid, Galalith

Manufacturing process:   extrusion; fabrication, usually machined to shape from sheet, rod or block; textures achieved by laminating sheet on sheet

Cost:   medium

Colour:   any, including mottles, pearls and special effects

Transparency:   usually opaque but some translucency when imitating tortoiseshell, horn and all the many decorative affects that could be achieved

Rigidity:   firm but can flex

Feel:   hard

Smell:   occasionally of the formaldehyde used in its production

Other:   accepts surface dyeing; polishes to a brilliant lustre

Typical uses:   buttons, knitting needles, fountain pens, jewellery, dressing table sets, manicure sets,inlay in furniture

Degradation:   Surface crazes and cracks