DSF

I'm looking for plain square glass sheets approx. 120mm x 175mm but could be suitable for sublimation. Is there such a thing available?

The glass would need to have a polymer coating as you can't sublimate on glass also I doubt 2 mm glass will withstand the heat press without shattering.

Depending what you're printing onto them UV may be a better option as they wouldn't need the coating.

yes your right i didn't think about the fact 2mm glass would probably crack under the pressure of the heat press. I was looking for a home made method of printing so thought a sublimation set up to do this would probably be best. Whilst UV would be ideal, I would have to outsource this as the cost of set up is far too expensive so unfortunately wouldn't be an option. The only other alternative I can think of would be to use waterslide decal sheets over the glass but this is the poor mans method and not the best finish.

Would you want the print to be completely opaque, or would you want some areas to remain transparent?

It's not the pressure that will crack it, I would think it would be the heat.

Would sublimated clear acrylic sheets work as a substitute? It can be bought in various thicknesses.