Medium weight wool is the choice where a substantial knit matters more than fineness. One hundred percent merino is the versatile everyday option, and Knit-On house brand pieces usually use superfine 18.5 micron Australian merino. Merino and cashmere blends balance the softness of cashmere against the durability of merino. Mongolian cashmere sits at the top of the ladder, and it costs more because it is a premium natural fibre.