Fabric buttons is a general term to cover all buttons made from fabric, thread, braid, beads, crochet etc. I think these buttons are from the early 1900’s. They are fine thread and braid wound over a button mould (probably wooden) in a diamond like pattern. They have no shank as such and you just catch a few threads at the back to sew them onto the garment. They measure a little under 1 1/2 cm.
All things buttons & more …