Where to get bakelite sheet off-cuts?

I am looking for somewhere using bakelite/phenol/fibre sheeting about 1,5mm thick - the kind of thing used for printed circuits. I do not need as large (and expensive!) as a full sheet will be - a few pieces of about 120mm x 60mm or such. I have tried transformer manufacturers but they mostly use thicker stuff.

I am in the Pretoria area, but Jo-burg might also do.