To all the black concrete tub rack users

You are better off making a tight fit with the tubs and then cutting of the little tabs on the underside of the tub lip to perfect the thickness where needed.

We didn't bother trying to suit each level for a certain tub. Overall your going to swap them out here and there when cleaning and washing.

Make it as tight as you can, over time the cloth will wear down the plastic tub rim just enough to make it glide in and out smoothly and it may even end up sagging just a bit. ;)