I’ve made a few sleep masks before I decided to create this one. I wanted to create a sleep mask that effectively blocked out all light, while being comfortable to wear night after night. I found that one layer let in too much light for me, and two layers really works well. The shaping around the nose is designed to contour over your nose so light doesn’t come in between the mask and your face. Using soft natural fibers makes it so comfortable to wear, you won’t miss a moment of precious sleep. I use mine every night for the past 10+ years, and sleep better with it. I have used silk/bamboo yarn, which had stretched out and lost its shape, while the cotton retained its shape and was comfortable enough to sleep in. Just be careful about shrinkage when washing!