While cleaning my cats' litter box, I got tired of holding a plastic bag in one hand and scooping litter with the other. So I tried to design a stand that could easily hold the bag, but leaving space to get a full bag of litter out. After trial and error, I ended with this model with 3 curved legs and a ring to fit the bag around. To keep the bag in place I completed the design with a cover that fits arround the top ring. The bags should be 28 cm wide, so they can fit around the ring. I've included a picture of the bags that I use.