These vintage buttons are an unusual shape and an interesting colour combination.. 

The black edge is built up in steps then swoops down into the intense green concave centre.

The buttons are made of plastic and I have them in either

1.5cm - 24 buttons

1.5cm - 6 buttons

2cm - 24 buttons

2cm - 6 buttons

I found them in an old button warehouse - they're Italian - probably from the 1960s, maybe earlier.