(Re) Learning the Blanket Stitch

A couple weeks ago I started a pair of slippers for Mr S.  The knitting part was easy, and the slippers are done. But it's critical to fix the bottoms so he doesn't slip on the wood floors, so here I am trying to sew some leather on the sole. It's very slow going because each stitch has to be negotiated through the thick yarn. I thought I was pretty clever to pre-punch holes in the leather with an awl, but they become invisible quite quickly, or maybe it's the light. There are four pieces, two heels and two toes, and it's taking FORever. A labor of love.