Lyocell is similar to viscose in that it is a regenerated cellulose fabric, but is made with a more eco-friendly process. TheU.S. Federal Trade Commissiondefines lyocell as rayons “composed of cellulose precipitated from an organic solution in which no substitution of the hydroxyl groups takes place and no chemical intermediates are formed” — essentially meaning it does not use the harmful chemical solvents normal viscoses use. Lyocell production also results in little waste product, but it is still relatively energy intensive.
Thread count is another important factor, but not in the way it is popularly conceived. The common knowledge about thread count is that higher is always better, but that’s not always true. In fact, brands selling sheets with astronomically high thread counts in the thousands are usually fudging the numbers with double-ply threads or other sly methods.