The two things to consider when looking at a sheet set are 1) the material it is made with and 2) the weave or knit style. Materials are the fibers — raw materials not formed into fabric — and weave or knit as the form of construction used to make the fiber into a cloth. The same material can feel different depending on the weave or knit style, and the same weave or knit style can feel different depending on the material.