, about $100 if I use Strathmore, a competing paper, which is only 25 percent cotton rag.
Strathmore costs about $100, but is only 25% cotton. 
mnli hypothesis: Strathmore costs about $100, but is only 25% cotton.  premise: , about $100 if I use Strathmore, a competing paper, which is only 25 percent cotton rag.