How embroidery designs are digitized

What digitizing is

A digitizer imports artwork into embroidery software and draws shapes over it. For each shape they pick a stitch type, direction, density and underlay, then decide the order in which everything is sewn. The software calculates the individual stitches and saves a working file plus the machine file for stitching.

The three stitch types

Satin columns get loose and snag-prone when they are too wide. Above roughly 7 to 10 mm, digitizers split them or switch to a fill.

Density and stitch length

Density is the distance between rows of stitches. Typical starting values are about 0.4 mm for fills and 0.35 to 0.45 mm for satin with standard 40 wt thread. Lower density (bigger spacing) is softer and faster; higher density covers better but can become stiff and pucker the fabric.

Fill stitches are commonly 3 to 4 mm long and running stitches 2 to 3 mm. Very short stitches can shred thread; very long ones snag.

Underlay

Underlay is a layer of light stitches sewn first. It anchors the fabric to the stabilizer, lifts the top stitches so they look fuller, and keeps the fabric from showing through.

• Center run: a single line down the middle of narrow satin columns.
• Edge run: runs just inside the edges, giving crisp borders.
• Zigzag: a loose zigzag under wider satin for loft.
• Lattice or tatami underlay: a light fill at an angle under large fill areas.

Pull compensation

Every stitch pulls the fabric toward itself. Shapes therefore come out narrower in the direction of the stitches than they were drawn, and outlines stop lining up. Digitizers add pull compensation, a little extra width, commonly 0.2 to 0.4 mm and more on stretchy fabrics.

Sequencing and trims

A well-sequenced design stitches from the center outward and from the back layer to the front, groups areas of the same color, and travels under later stitches where possible instead of trimming. Fewer trims and color changes mean faster stitching and fewer loose threads.

Digitizing for the fabric

• Towels and fleece: stronger underlay, a knockdown stitch or topping so the stitches do not sink.
• Knits and T-shirts: lighter density, more underlay and pull compensation, cutaway stabilizer.
• Caps: stitch from the center outward and from bottom to top to avoid distortion.
• Leather and vinyl: lower density, because every needle hole is permanent.

Small lettering

Lettering is usually readable down to about 5 to 6 mm in height for capital letters with standard thread. Smaller text needs special fonts, thinner thread (60 wt) and a smaller needle.

Auto-digitizing

Many programs can convert a picture into stitches automatically. It is useful for simple shapes and quick tests, but it cannot make the judgment calls above. For logos and anything you will stitch many times, manual digitizing gives a much cleaner result.

Digitizing software

• Professional: Wilcom EmbroideryStudio, Pulse, Tajima DG/ML.
• Hobby and prosumer: Hatch Embroidery, Brother PE-Design, Janome Artistic Digitizer, mySewnet (Husqvarna Viking and Pfaff), Bernina Embroidery Software, Embrilliance StitchArtist, Embird.
• Free and open source: Ink/Stitch, an extension for the Inkscape vector editor.