I was emailing back and forth to Jon at SolerComposites.com
He was telling me the 3K twill carbon he usually sells is 20% stronger than Torray’s 3K twill. I was amazed that there would be so much difference from one brand of cf to the next. If you guys are curious to know he sells his 3K for $29 per yard.
I’ll probably aim for 1.5mm then on thickness. I will peel ply the backside so if i need to i can add more layers on the prototype part.