We decided from the start we wanted to make a dog bed that was natural, healthy, and resilient. We spent a considerable amount of time experimenting with various materials. Again and again, we came back to cotton canvas as it is the absolute best material for the lining and cover. It met all our requirements. The cotton is 100% GOTS certified organic and is sourced from abundantly grown plants. It is healthy by virtue of being grown without the use of pesticides or any other harmful chemicals. This is most important as the fabric will come in direct contact with your pet. Lastly, it is an extremely resilient material and may be washed countless times without degradation.