• Casein: high polish on front, satin glass OME

    Casein identification guide: casein is a thermoset semi-synthetic polymer made from milk, hardened in formaldehyde.

    8. Takes a high polish, but the back may be less polished, helping to differentiate from Bakelite, which is tumble-polished on all sides.

    This button has two OME’s — white metal and blue satin glass.

     

    source: Button Materials A-Z: Identification Guide
    by Jocelyn Howells

    Button Specs