Cloth material on both sides. Glad its not a plastic sided mattress. This is good because I didnt want a plastic feel or sound on the mattress (though I also ordered a soft mattress cover just in case). It is 2 stages like it said. Infant and toddler.  Doesnt feel like cardboard  at all or anything hard. This is the perfect soft yet well supporting mattress . Just waiting for our grand baby to arrive to test it out. Will follow up later to update.