I made some for a friend's MIL. I call them aprons-instead of Adult Clothing Protectors-because I think they look a bit like the old fashioned aprons my grandmother wore.
I made them long enough to cover the entire lap when seated. Adapted a pattern I found online. Used cotton on one side, towel on the other and added a pocket for tissues or napkins on the front (cotton side) and snap closure. They were a big hit and easy to make.
Pat