We've done several dozen of the Sanmar 'work jacket' which is identical to the Carhart, but has the 'hidden zippers' to make life so much easier! Did do a jacket right through both layers before we found the zipper... Seems I remember the settings 'using' the zipper pocket (so we only went through one layer of canvas, plus a 2 oz. backing we sprayed with adhesive to hold in place) at around 10. I will have to see if we wrote notes on it and saved them. Back of the jackets had 67,000 stitches, front had name on one side, 15,000 on the other. Going through both layers and quilting I think we ran up around 14 or 15. Depends on the stitching also. We did do one Carhart the client already had-and that jacket had a seam right down the back-broke needles, and had to increase to around 18 I think. Was not happy with the quality at all on those-the Sanmar jackets were far superior and customer reordered twice. Worst problem was hooping them-material is so thick that the hoop screw was almost at the limit. Had to put adhesive back tape around both inner and outer hoop to hold the material. (also why we had to use a layer of backing inside the jacket back with adhesive-to keep the hoop from skidding) and then had to use heavy duty 'wedge' clamps to keep the hoops from popping open. Once we got the system of hoop, backing, and clamp working it took approx. 2 hours PER JACKET to get all the embroidery done. Roland