There's really no comparison between natural and synthetic materials - our bodies know the difference and when given the choice, my preference is always to use products made with materials straight from nature. It's why I chose an all cotton cover for the Feel Good Mat. Natural materials just feel better on our skin and when we feel better, we can relax more. This is a list of favorite natural picks that keep me feeling good while staying easy on Mother Earth. naturalproducts nontoxic cotton wool