That's due to oil barrier. I like that idea, desire I had thought of it!! Having said that, that's, I now 3D print cat food bowls that have an incredibly modest, canted inward oil ring, which stops kittie's fur from accidentaly acquiring oily. It works really well and is easy https://pet-shop-dubai66653.blogsidea.com/42801346/the-smart-trick-of-pet-supplies-online-that-nobody-is-discussing