Has anyone ever used "an extra thick card stock" for heat pressing cloth and using it as a protectant from the sublimation bleeding through the material to the other side? looking to find out the weight of that paper, we have a few in our warehouse, I've compared it to card stock and watercolor paper, and its much thicker than both of those. it looks like cardboard on one side and has a white surface on the other, but its not corrugated either. struggling to find. sos! the thickest ive compared it too is 300 g/sm and it is still much more sturdy than 300