These bakelite bangles are so different and make an interesting stack.
Top bangle is line carved corn with red overdye and measures 5/8" wide X 2 1/2" wrist X 1/4" wall thickness.
Second from top bangle is half and half laminate in marbled red and corn measuring 5/8" wide X 2 1/2" wrist X 5/16" wall thickness.
Third bangle is corn tambourine bangle with pink celluloid rings measuring 1/4" wide X 2 1/2" wrist X 3/8" wall thickness, not counting the pink rings.
The bottom bangle I've seen attributed to Martha Sleeper and is rope carved corn with red and pink paint measuring 9/16" wide X 2 1/2" wrist X 3/8" wall thickness.
