Reference: File Formats

StitchKit can read (import) many embroidery machine formats and write (export / send to machine) most of them. The table below shows which operations each format supports and whether the file carries color (thread) information. This information is taken directly from StitchKit's parser code; your machine's actual support may vary by model.

Format comparison table

Format	Extension	Read	Write	Typical machine / use	Color info
DST (Tajima)	.dst	Yes	Yes	Tajima and most industrial machines; the industry's common "interchange" format	Not carried — the file has no colors, only a color-change marker. StitchKit assigns a default palette; the real thread colors are stored in a sidecar file (see below).
PES / PEC (Brother)	.pes, .pec	Yes	Yes (writes .pes)	Brother, Babylock, and Bernina Deco home machines	Carried — the color is stored as an index into the Brother PEC thread palette. On write, your color is matched to the nearest thread in the palette (not exact RGB).
JEF / JEF+ (Janome)	.jef, .jef+	Yes	Yes	Janome / Elna home machines (JEF+ carries an extra metadata block)	Carried — as an index into the Janome thread palette. On write, it's matched to the nearest palette thread (not exact RGB).
EXP (Melco / Bernina)	.exp	Yes	Yes	Melco and Bernina machines	Not carried — like DST, it's a headerless raw stitch stream; it carries only a color-change marker, with no color data.
VP3 (Husqvarna Viking / Pfaff)	.vp3	Yes	Yes	Husqvarna Viking and Pfaff machines	Carried (fully) — each color block embeds true RGB plus the thread name/catalog information.
XXX (Singer / Compucon)	.xxx	Yes	Yes	Singer and Compucon machines	Carried (fully) — true RGB values are stored in a color table at the end of the file.
U01 (Barudan)	.u01	Yes	Yes	Barudan / some industrial machines	Not carried — there are color-change/needle-change markers but no color data; StitchKit assigns a default palette.
SHV (Husqvarna)	.shv	Yes	Yes	Husqvarna Viking (older generation) machines	Carried — as an index into an internal thread palette. On write, it's matched to the nearest palette thread.
SEW (Singer Futura)	.sew	Yes	Yes	Singer Futura machines	Carried — as an index into the thread palette. On write, it's matched to the nearest palette thread.
HUS (Husqvarna Viking)	.hus	Yes	Yes	Husqvarna Viking machines	Carried — as an index into a 29-color internal palette. On write, it's matched to the nearest palette thread.
VIP (Pfaff / Viking)	.vip	Yes	Yes	Pfaff and older Viking machines	Carried (fully) — true RGB values are stored in the palette (in encrypted form).

Windows — To import a file, use the file-open dialog in the editor; all the "Read = Yes" formats above are listed. When exporting, choose your target machine's extension.

Which format should I choose?

If you're not sure, use DST. DST opens on almost every machine and is the industry's common format. The downside: it carries no color information.
If you want the colors to come out right, prefer your machine's own format: PES for Brother, JEF for Janome, VP3 for Viking/Pfaff, XXX for Singer, and so on.
If you need true RGB color, VP3, XXX, or VIP are the best choices; they store color as full RGB rather than as an index.

How is color information preserved?

In color-carrying formats (PES, JEF, VP3, XXX, SHV, SEW, HUS, VIP), StitchKit writes every color in your design to the file. In index-based formats (PES, JEF, SHV, SEW, HUS), your color is automatically matched to the nearest thread in that brand's thread palette — which is why the color on screen and the color on the machine may show small differences.
DST, EXP, and U01 don't carry color. In these formats, StitchKit only preserves the color change points; to preserve the colors themselves, StitchKit writes a color sidecar file next to the file (with the same name, .colors.json).
Thanks to this sidecar in the same folder, when you reopen a DST/EXP file in StitchKit, your real thread colors are restored. If you move the file to another computer or machine without taking the sidecar along, the colors revert to the default palette.

Tip — If you work in a format that doesn't carry color (for example DST) and also want to keep your colors, keep the file in the same folder as the .colors.json sidecar StitchKit creates.

Note — When you prepare a multi-color design and write it to a format that doesn't carry color (DST, EXP, U01), whoever opens the file in another program sees the design in default colors. In index-based formats (PES, JEF, SHV, SEW, HUS), the color is rounded to the nearest palette thread; it may not be exactly the same as the color on screen. Only VP3, XXX, and VIP preserve full RGB color.

Note — You can read PEC (.pec) files, but StitchKit writes PES (.pes) instead when exporting; the PES file already contains the PEC stitch block, so it works on Brother machines. Similarly, writing JEF+ uses the same engine as JEF and adds an extra metadata block.