How wide do you make your welts and do you stitch down the center of that width?
I've never measured but guessing probably 3/8" leaves you plenty to belt sand the edges true flat, try to stitch down the center but don't always make it!
Yeah what LC said. But I do use an old compass to guage with makes it lot easier.
Mine are about 1/2" so it leaves some extra to sand down. I also super glue them in before stitching so they won't move and it helps me get down the middle.
For mr welt width and thickness varies with the blade. Thickness matches blade thickness, and width matches the size of the blade. On a small knife I will sometimes taper the welt and will most always use a pin or copper rivet to protect the stitches at the top edge side of the sheath.
They average 3/8 for me.