6/8 to 7/8 1/4 hollow for me. I have one blade at 9/8 and it's heavy, shaves great but I have to say my hand gets a work out when I use it. Also as Walter said, my hands have never been steady either so the 6-7/8 size range calms thing's down. They all work as was said, but the added weight is like power steering over a lighter blade.