Either wheat pressed or bamboo, they're light and a little harder than most plastic plates.

I bought these for my youngest to try to help his dinner times by separating his food. After using just a few times I've decided to sell for something that fits my limited cupboard space.
These were helpful for us dealing with difficult dinner times, autism and Avoidant/Restrictive Food Intake Disorder (ARFID) hopefully they'll be useful again for someone else.

They're great quality. Think I paid about ten pounds each. The plates dishwash just fine. they get a little warm in the microwave depending what's on them but were sold as microwave safe. Although they stack fantastically, and helped us with dinner times we've switched to clear out cupboard space. children's plates. super for adults kids children who prefer their foods separated.