▶ Watch the step-by-step video (YouTube)
When continuing to punch, overlap the last hole by one tooth so that the stitch line stays straight and the pitch stays even.

Following the guideline you have drawn, set the chisel against the leather—taking care that its blades do not cut it—to mark the positions, then punch the holes.
▶ Watch the step-by-step video (YouTube)
When continuing to punch, overlap the last hole by one tooth so that the stitch line stays straight and the pitch stays even.