Cretan stitch:This is a variation of the feather stitch. This is done by making two slanting outer stitches, one to the right and one to the left of the stamped line. The center forms a ribbed effect. It can make an effective border.
"Double Back Stitch" -- This may be the same stitch that was used on the items that I pinned made in Mexico in the "traditional Mazahua" style or method. (This looks like it might be more complicated and more dense though.