Types of machine embroidery stitches
Every embroidery file is built from three stitch types. Knowing which one goes where explains why one logo looks crisp and another looks stiff, gappy or puckered.
Running stitch
One stitch after another, in a line. Used for fine outlines, small details and for travelling under other areas without showing. On outlines it often runs two or three times to be visible.
Satin stitch
The thread goes from one side of the column to the other, very close together, giving embroidery its shine. It is the stitch for letters and borders. It works on narrow columns: too wide and the thread is loose and snags; too narrow and it bunches.
Fill stitch
Rows of short stitches that cover large areas, like the background of a crest. It accepts texture and direction, and it is what holds a large design together without getting loose.
Underlay
Before the visible stitches, the file sews an underlay that holds the fabric and supports the top thread. Without it, satin sinks and fill shows the fabric between stitches.
Why it matters in your order
Size decides the stitch. The same letter can be satin at 10 cm (4 in) and need to become fill or be redrawn at 3 cm (1.2 in). That is why the file is digitized for the size and fabric you tell us.