MACHINE EMBROIDERY
Tatami and satin are not interchangeable “fill styles”. One is a coverage stitch, the other is an edge stitch. Using satin where tatami belongs makes a design stiff and slow; using tatami where satin belongs makes edges look fuzzy.
Tatami: coverage with a direction
Tatami is a back-and-forth fill with a deliberate row spacing. It is the workhorse for large areas: leaves, backgrounds, cup shapes, badges and photo-like colour blocks. The visible lines are part of the texture, not a defect. A row spacing around 0.35–0.45 mm is typical for a solid fill on woven cotton; adjust for thread weight and the look you want.
The fill angle matters. On a leaf, follow the long axis so the thread carries the eye toward the tip. On a curved cup, a consistent angle across the whole shape reads calmer than a different angle in every sub-shape. Underlay runs across the top fill and gives the top rows something to sit on.
Satin: an edge, a column, or a highlight
Satin is a dense zig-zag across a narrow column. It is excellent for borders, lettering, thin stems, outlines and small highlights. It is a poor choice for a wide area: the long stitches are easy to snag, the fill is heavy, and the density can pucker the fabric.
A satin border needs a true outer rail and a clean inner rail. The stitch spacing should be tight enough to cover but not so tight that the thread stacks. Satin lettering needs a minimum stroke width; below roughly 1.5 mm, the needle and thread cannot form a clean column, and the letter fills in.
Where each one belongs
| Element | Better default | Why |
|---|---|---|
| Large leaf or cup fill | Tatami | Even coverage without a stiff board |
| Patch outer edge | Satin or merrow | Defines the shape and seals the edge |
| Lettering above 4 mm | Satin | Sharp stroke, clean counters |
| Lettering below 4 mm | Different method | Needle and thread cannot hold it |
| Thin outline | Running or satin column | Follows the line without a wide fill |
The sheen question
Satin reflects light across the column, so it looks brighter and more directional. Tatami shows many small ridges, so it reads more matte. That is useful: use satin where you want a highlight or a boundary, and tatami where you want a calm surface. A design that uses satin everywhere looks metallic and heavy; one that uses tatami everywhere has no crisp edges.
Density is not a quality score
More stitches are not automatically better. Oversewing a fill can make the patch stiff, increase thread breaks, and hide the source colours under a layer of specular highlights. Start with a sensible spacing, test on the actual fabric, and only increase density where coverage fails.
If you are unsure, render the front preview at full size and look for the fabric showing through the fill. Then check the edge: a clean satin border should read as a continuous line, not a row of teeth.