I believe a pricking iron is a must for this stitching. The holes used by Hermes and others with sloping stitches are different. Instead of a diamond shape hole, the have slanted slits. If you want your thread to go //////////////, you need portmanteau (left) pricking irons that look like \\\\\\\\\\\\\\\\. If you get a vintage suitcase and pop out all the old thread, you'll see a WWWWWWWWWWWW like impression on the leather. the slants going towards the left are thread marks and the slants going towards the right are the actual holes punched in. Somewhere on this forum, someone said he or she spoke to a Hermes artisan about the pricking iron and the artisan said she actually hammers the iron all the way through instead of just "pricking" the leather. In a Alfred Dunhill video, he pounds his pricking iron hard too, so they both pre make the holes. In both Hermes and Dunhill videos, you can see an awl being used, but it's just to guide the back needle through since you can't see the back hole without bending over to look. It's also how you pull the thread as well. I'm probably going to order a Dixon iron soon, so I'll pit it to the the test and try different methods.