Blackwork, sometimes historically termed Spanish blackwork, is a form of embroidery generally worked in black thread, although other colours are also used on occasion, as in scarletwork, where the embroidery is worked in red thread. Originating in Tudor period England, blackwork typically, though not always, takes the form of a counted-thread embroidery, where the warp and weft yarns of a fabric are counted for the length of each stitch, producing uniform-length stitches and a precise pattern on an even-weave fabric. Blackwork may also take the form of free-stitch embroidery, where the yarns of a fabric are not counted while sewing.

Backstitch or back stitch and its variants stem stitch, outline stitch and split stitch are a class of embroidery and sewing stitches in which individual stitches are made backward to the general direction of sewing. In embroidery, these stitches form lines and are most often used to outline shapes and to add fine detail to an embroidered picture. It is also used to embroider lettering. In hand sewing, it is a utility stitch which strongly and permanently attaches two pieces of fabric. The small stitches done back-and-forth makes the back stitch the strongest stitch among the basic stitches. Hence it can be used to sew strong seams by hand, without a sewing machine.