Casein plastic button; two part in two tones - navy/red, navy/cream, cream/beige, cream/cream.
These buttons are super cute, and althought they have been manufactured with the finer rim to the front, they look great either way - you choose.  
Unfortunately some haven't been kept in optimum storage conditions. While we have sorted out the best of them, the lighter shades of cream/cream, and cream/beige, show some yellowing glue marks. 
 
European, original 1940s-50s.
18mm diameter; 2 hole sew through.