Before designing our sheets, we had to rethink everything we thought we knew. We learned that a higher thread count doesn’t mean higher quality, you can’t cut corners when it comes to cotton, and the right weave makes a world of difference. Our result? Sheets that are the perfect balance of soft, crisp, and airy. Instead of obsessing over the number of threads, we focused on finding the right thread count for our specific cotton and weave choices. A high thread count sounds fancy, but more threads can actually make sheets heavier and less breathable. We landed on 400 two-ply threads — a modest number that makes a big difference. We chose a lightweight percale weave because it’s proven to last longer and breathe better than any other. It features a classic one-over-one pattern that will give you cool, crisp comfort for nights on end. Supima is one of the longest cotton fibers in the world. It’s 35% longer and 45% stronger than regular cottons, which means the fiber is even softer and more lustrous wash after wash. It’s a big part of what makes the Casper sheets naturally soft. The Supima cotton used in Casper sheets comes from a farm in California’s Central Valley. The Casper sheets are designed in the USA; Spun, woven and sewn in India, and made with Supima cotton from California. These sheets will fit any mattress up to 14 inches high.