Answered: Different materials within plastic sheet size limit

I was wondering whether of not it is legal to use multiple different kinds of plastic within the parameters of the size constraints.

For example, would it be allowed to use a 12" x 12" sheet of abs and 12" x 12" poly carbonate? Obviously both are of the correct thickness and would be perfectly legal if used without the other. As well, both the sheets would fit within 12" x 24" sheet if the sheet was made of half abs and half polycarbonate.

Yes, this is legal, provided no other rules are violated in the process.