I was browsing the Valery Demure online shop and noticed this Fox brooch in the Rarities section. The designer is french artist, Lea Stein. She known as “the most notable and innovative designer of plastic jewelry of the 20th century”. She started working in textiles in the late 50s but eventually grew interested in plastics in the mid 60s. She married a chemist and together they created a new layering technique for plastic.
She worked with her husband, chemist Ferdinand Steinberger, to develop a process of layering very thin sheets of cellulose acetate (or rhodoid) and laminating them to form a “multi-coloured sandwich of plastic”. Each ‘sandwich’ was baked for a long time, then cooled and cut into shapes. The process could take as long as six months. This technique allowed Stein to insert different fabrics (such as brocades and lace), colors and textures into the plastic.(source)