@emma @Inginsub @bot I remember trying one of these little flap disc attachments for drills (for people who are too cheap to buy a dremel) and I ended up finding sandpaper was easier purely because of the difference in surface area. I don't remember being in any danger of putting a dip in the surface however (mind you I was being careful because I had the same fear you did), I actually ended up swapping to one of the harder nobby ones in the kit only to be similarly frustrated.