Dome-shaped light weight metal buttons. The buttons will vary a bit in size, but I have them sorted to have like ones together. Metal shank for sewing or stringing on cord. They are all what I call dusty brass. Meaning they are not shiny at all.
A note about attaching these buttons. No joke it can be a PITA if you try sewing them on individually. So what to do? String them onto a cord, yard, trim, or anything you can think of and sew them down.