I mentioned going down the WW2 micro-armor rabbit-hole a few posts back. I found some rather inexpensive basing material on Amazon a couple weeks ago which showed up yesterday.
Boom! 175 1 x 1 x 1/8 plastic squares for about $8.00. Not shabby. They are made of hard plastic.
A 6mm M48 Patton for size reference.
I dug these up a couple of weeks ago.