Satin or fill: which to use, and where the changeover is

Satin lays long stitches side by side across a shape, so the thread catches the light along its whole length. That gloss is why lettering and borders are satin. A fill covers an area with rows of short stitches and looks matt by comparison, because the light hits it from many directions.

The rule is width, not shape

A satin stitch spans the whole shape in one go, so the wider the shape, the longer the stitch. Past roughly 12 mmthose stitches snag on the presser foot, catch on fingers and jewellery in wear, and eventually pull loose. Beyond that width, use a fill.

Between about 8 and 12 mm, satin still works but wants auto split turned on, which breaks the long stitches into shorter ones that hold the surface without losing the gloss.

Where each one wins

• Satin: lettering, outlines, borders, stems, anything narrow that should look raised and glossy.
• Fill: backgrounds, large shapes, anything where you want the fabric fully covered without a ridge.
• Both: a filled shape with a satin border is the standard way to make an area look crisp, because the border hides the ragged edge of the fill.

Narrow shapes that are not straight

A satin round a curve needs its stitches to turn with the curve, or the outside edge opens up and the inside piles. That is what the stitch angle guides are for. On a shape that changes width a lot, a fill that follows the shape is often cleaner than fighting a satin.