Thick.Nice. old Boxer with ortho issues likes it. Update: Getting 2 more for the floor next to my bed cause toy breed fell off the bed once due to an ear infection induced vertigo & other toy breed going blind so if he falls off the bed they will be cushioned & avoid injuries, pain & big vet bills. You could also use as a 4" step next to a sofa for tiny breeds. Cover comes off on easy & washes good, no dryer