Tradition holds that blackwork was imported to England by Catherine of Aragon, the first of Henry VIII's six wives. Catherine was the youngest surviving child of Spanish monarchs Ferdinand and Isabella, and because of this connection with Spain, blackwork is sometimes referred to as "Spanish stitch" or "Spanysshe work." However, geometric stitching in silk on linen, very much like Tudor and Elizabethan blackwork, is found in Moorish embroideries executed centuries before Catherine lived.

Blackwork can be worked using any one of a number of outline stitches, among them back stitch, stem stitch, and split stitch. However, in order to make blackwork reversible, one must use a stitch called the double-running stitch, or Holbein stitch. This stitch is best worked on even weave material.

How To Start Stitching
One of the first questions asked about reversible blackwork is how to start stitching without an obvious knot on the back of the work. The answer is quite simple, and I learned how at a class at Pennsic XXVIII, taught by ----.

Cut a length of embroidery floss twice as long as you will need. Separate one strand of floss and double it, making sure that the end are even. Thread your embroidery needle with the two ends, leaving the loop end hanging.

Push the needle up from the underside of your work, leaving the loop underneath. Make your first stitch, putting the needle through the loop at the end of your thread. Pull the loop snug. It helps to tug knot (the junction of loop and free end) towards the direction in which you are working; the work will lay flatter than way.

How to Stop -- I mean End -- Your Stitching
One of the second questions asked is how to end your stitching without an unsightly knot in the middle of your work. The easiest way I have ever seen is to loop the thread around previously sewn stitches, in essence sewing a whipstitch around the stitches themselves, never going back through the ground fabric. Then snip the threads as close to the work as possible.

It's important to note that you should stop stitching the first journey with plenty of floss remaining to complete the second journey. It is very difficult to start thread in the middle of the second journey and makes your stitching looks very odd.

I Have Lots of Floss Left -- What Do I Do?
I'm a Yankee. I hate to waste unused floss -- especially when it can cost up to $0.25 a skein (is there any wonder I stock up when I go to New Hampshire? It's only $0.19 a skein at the A.C. Moore in Nashua!). There is something you can do when faced with enough Floss for another short run of stitching: Tie a knot in the thread close to the ends. Clip the ends very close to the knot and start your stitching as outlined above. This isn't as clean as starting over with a fresh piece of looped floss, but if you're not too worried about knots, it's better than throwing away that piece of perfectly good floss that isn't long enough to double over. I wouldn't recommend doing this on a reversible piece worked for a competition, however.