This is a type of strengthened Double backstitch. It is done from right to left pulling the needle on the front side of the fabric, grabbing three or four threads of the fabric to the right, pulling the needle again in the same spot where we started. Then, we pull the thread in such manner that the stitch is tight. We work on a second Stitch over the first one, again pulling the thread so the second stitch is also tight. This time, we pull the needle three or four threads to the left. We continue working like this, pulling the thread to form small columns.
