I mentioned it earlier in the thread. you can't mix wool and linen. That mixture is called shatnes.

Shatnes is not Kosher.

Quote Originally Posted by davedove View Post
It's not that the typical wool kilt is made that way, but a lot of cloth is made by mixing materials.

I believe there is a Jewish prohibition to wearing clothes of "mixed cloth". By labeling it as non-mixed, it is okay to wear. Someone more knowledgable than I will have to verify that.