I mistakenly got the Embroidery foot 39C before getting this Reverse Pattern foot 34C. The bottom of the feet are quite different. Embroidery 39C is carved out behind the needle hole so there is no contact with the center feed dogs behind the foot. Good for embroidering bulky-thread designs, but bad for grip over regular seams. Reverse Pattern 34C is flat behind the needle hole, so it uses the central feed dogs, is better for stitch length control, edge stitching, and going over lumpy seams. Same feed dog contact area as the metal Reverse 1C.

