What's the best duvet cover material: cotton, linen, or microfiber?

Across the reviewers we read, 100% cotton (percale or sateen) earns the most consistent praise for breathability and longevity, with washed-cotton 'linen look' fabrics close behind for people who want a relaxed, lived-in texture. True linen is loved for cooling but costs significantly more. Microfiber is the budget pick and gets called out repeatedly by specialist communities for sleeping hot and feeling slippery, even when Amazon ratings stay high.