Chris,I put a layer of 6 oz. cloth in the mold,then a bunch of 12K tow,cloth,tow,and a last layer of cloth on the outside.It's mostly tow.I like the look of the weave and the stability of the perpendicular fibers in the cloth.I'll be making another mold for a set for 40 size ships this week with the same shape as these.They have a certain shock absorbing quality,can't wait to get them on a paved circle