Hi Beth: Your buttons are molded ceramic with white and black fired on color highlighted with gold luster. If are going to be listing these for U.S. buyers, try to report the size in inches, not many of us know centimeters to make any sense of it, sadly. The applied shanks are probably celluloid rather than bakelite. I would list them like this: "Vintage Gold Lustered Modified Square Ceramic Buttons" They seem to be from the 1940-50's. Appeal of buttons like this to collectors is limited to the modified square shape. If these had a pictorial design (some type of design you can recognize as plant life, animal life, object or people, scenics, etc.), they'd have more appeal. Best of luck with your sales. -Carol C-