Detached Up & Down Buttonhole Stitch (DUDB) is used to fill solid areas. Like Buttonhole Stitch, it can also be worked as a 'chorded' stitch (where a bar, or chord, is run across the fabric surface, and the stitches are worked over the chord). It creates a lovely textural effect that works well for leaves and flowers, etc. Shown here is a leaf worked in chorded DUBH. (I will add a tutorial for the chorded version in the near future).
DUBH can be worked in silk, cotton, and the more pliable metal wires. Tightly twisted silk threads are nice for adding more texture to the stitch. For this tutorial a silk perlee that is slightly heavier than Au Ver a Soie's perlee was used, on 50 ct. linen.
Secure working thread with an away waste knot. Stitch a row of back stitches from right to left. Bring needle to fabric surface about 1/8" below backstitched line. Slide needle down under the first backstitch as shown, being sure that the working thread is under the tip of your needle. Pull the needle through. This will create one buttonhole stitch.
Next, run the needle back up under the same back stitch, with the working thread held above the backstitched line, and under the needle, as shown at left.
Pull the needle through and tighten the stitch, lightly, by tugging downwards on the needle. One DUDB has been completed.
Repeat the above two steps for each backstitch, thereby completing one DUDB for each backstitch.
After completing a row, take the working thread to back of fabric and bring it back to the surface about 1/8" below the last row, to begin your next row.
Subsequent rows are worked in the loops between each DUDB as shown at left.