I like to use a silk pillowcase for my curly hair. However, a pillowcase constricts the flexibility and 'rise' of the pillow. It feels flat. Conversely, I have been using it without a pillowcase and even after washing it twice in one day, its still yellow. Why make a white pillow that you can't use a pillowcase with? Otherwise, its a great pillow--my neck pain is gone. Just doesnt seem functional.