Adding colour strip help needed?

[wcdurand]

Hi guys. Just want to test my thinking if you could help me. --- If I want to add a unidirectional coloured fiberglass strip in the middle of my stack and if my stack was normally.310 thick would the addition of the fiberglass strip neccessitate me to lower the stack thickness because of the stiffer fiberglass core say to about .300 to have the same poundage, Or would the fiberglass being in the middle of stack not have such a big effect on the poundage. My thinking is that the stiffer fiberglass would up the pounds, but by how much?

[wcdurand]

Might have to be moved to bowyers bench