When using abrasive paper on a substrate for sharpening, does it matter if the paper extends to the edge of the substrate or leave a border of 1/2" to 1"? — Avrum Silverman

Garrett Hack replies: What matters most is keeping the back of your plane irons and chisels flat on the sandpaper. The amount of border is a secondary issue. I find it easier to keep the pressure on the blade “flat” with no border, merely because I can better see what the overhanging part of my tool is doing.