These sanding sponges are ideal for modelling. Yes they are rough but they are not meant for final polishing. There are many microabrasives on the market for this purpose. The grinding material adheres very well to the sponge. This means that as you sand, you won't feel the abrasive grit loosen and the particles roll across the surface and scratch your work like cheap abrasives do. You can also cut two pieces and rub them together lightly until you get the right amount of abrasion needed for the job. Excellent product for seam lines and general sanding of models. You are a tool and you must use the right tool for your job. You don't use modeling clay or sandpaper from the hardware store to prep the kitchen counter for painting.