You shall not wear cloth of wool and linen mixed together.
#deuteronomy 22:11 #torah #kitetsei
This literally only applies to wool and linen. I believe it also means plant vs animal, wool and cotton for example, but that's me. Follow your conscience. Cotton+wool, cotton+synth, whatever... Your call, but there's no question about linen and wool. God says don't mix it and it isn't only allegorical.