DST, PES, EXP, EMB. What each one is for, which your machine needs, and the difference between a file you can stitch and a file you can edit.
Someone sends you a design and it won't open. Or it opens, stitches, and comes out the wrong colors. Or you ask for a change and get told it can't be done, on a file you paid for.
Nearly all of that comes from one thing people are never told: embroidery file formats split into two completely different kinds, and only one of them can be edited.
Here's the whole picture, in plain terms.
Stitch files are instructions for a machine. Move here, put a stitch down, move there, stop for a color change, trim. That's all they contain. Every needle position, in order, and nothing about why. DST, PES, EXP, JEF and the rest are all stitch files.
Source files are the design as objects. This shape is a satin column with this underlay at this density. That one is a fill running at this angle. Because the software still knows what each piece is meant to be, everything can be changed and the stitches get regenerated. Wilcom's EMB is the common one.
The difference matters enormously. A stitch file is a photograph of a decision. A source file is the decision itself.
Here's what that means in practice. Ask for a design to be made 20 percent smaller and, from the source file, it takes minutes: the density recalculates, the underlay adjusts, the lettering can be rebuilt rather than squashed. From a stitch file it can't really be done at all, because there's nothing in there that knows a shape was ever meant to be a satin column. All the software has is a list of needle positions.
People discover this at the worst moment, usually a year later when the person who made the file has moved on and a client wants the logo on caps instead.
Roughly, by where the machine came from:
Your machine's manual will say, and the control panel usually lists what it can read. If you're on an industrial machine you almost certainly want DST, and our walkthrough of loading designs on the A15 Pro shows the whole route from export to stitching.
DST does not store thread colors.
It stores color changes. Stop here, the operator will put something different on. Which color is entirely up to whoever is standing at the machine. That's why the same DST can come out looking completely different in two workshops, and why a design that arrived looking right on your screen turns out gray in the file.
This isn't a fault. It's a format built for production floors in the 1980s, where the colors were on a work sheet and the machine just needed to know when to stop. But it does mean two practical things.
First, always get the color list separately, as a note or a picture. Second, if color accuracy matters and your machine reads something richer, ask for that format as well.
This is where most disputes come from, and it's worth settling before work starts rather than after.
When you pay for digitizing, you usually receive the stitch file. The source file is a separate thing and most digitizers keep it. That's not sharp practice, it's the norm, and it's often what lets them offer cheap revisions later.
What it means for you is simple. With only a stitch file, another digitizer can make small adjustments but cannot properly rework the design. If you might change suppliers, or you want the design to outlive your relationship with whoever made it, ask about the source file at the quoting stage when it's still cheap to negotiate. There's more on what a quote should include in our guide to hiring an embroidery digitizer.
If the manual has gone missing, which it usually has, there are three quick ways.
Put a USB drive in with one design saved in several formats and see which ones appear in the machine list. That takes two minutes and settles it. Failing that, the control panel often names the formats in its import screen. And if you bought locally, the dealer will know instantly, which is one of the small reasons buying from someone reachable is worth paying for, as our guide to choosing the right embroidery machine argues at more length.
One warning while you are testing. Some machines list a file they cannot actually stitch properly, so confirm with a real run on scrap rather than assuming the file being visible means it is supported.
Plenty of software converts one stitch file to another, and for getting a design onto a different machine that's usually fine.
What conversion does not do is improve anything. The stitches were placed for the original job, and moving them into a new container doesn't rethink density for your fabric, doesn't fix underlay and doesn't re-sequence anything. You're renaming the box, not repacking it.
It also doesn't go backwards. You cannot turn a DST into a proper source file. Some software will read a stitch file and group the stitches into objects, which looks like the real thing and isn't. It's a reconstruction, and the original decisions about underlay and compensation aren't in there to recover.
Worth its own line, because it catches everyone once.
If you scale a stitch file, the stitch count stays the same while the area changes. Make it bigger and the same number of stitches has to cover more ground, so it goes thin and gappy. Make it smaller and they crowd together, so it goes dense and stiff. A few percent either way is fine. Anything more needs the source file and someone to rebuild it.
All of the above is about output. On the input side, what you send your digitizer matters just as much.
Vector artwork is best: AI, EPS, SVG, and often PDF. The shapes are described mathematically, so they stay clean at any size and are quick to work from.
Raster images are JPG, PNG and the like. Usable if they're large and sharp. A logo pulled off a website at 300 pixels wide, or photographed off a signboard, has to be redrawn before digitizing starts, and that rebuild is part of why digitizing costs what it does.
And to be clear about something people genuinely try: renaming a JPG to DST does not make it an embroidery file. There is no converter that turns a picture into good stitches, which is roughly the whole argument in hand digitizing vs auto digitizing.
DST, by a distance, because industrial machines read it and it's the safest thing to hand someone when you don't know what they're running.
To view it, yes, with free stitch viewers. To edit it properly, no. Viewing shows you what the stitches do; editing needs the design as objects.
Almost certainly DST doing what DST does. It only tells the machine when to stop, not what to load. Get the color list from whoever made the file.
EMB is Wilcom's source format, the editable version of a design. It needs Wilcom or something that reads it, and a machine cannot stitch it directly. If you were sent one on its own, ask for a stitch file as well.
Ask for what you run, plus one spare if you're likely to add a machine. Collecting formats you'll never use isn't worth negotiating over.
There are free tools that handle straightforward stitch-to-stitch conversion. If you're doing it often, that's usually a sign you'd be better off with the design built properly for each machine, which is what our Digitizing Mastery course teaches.
Embroidery file formats split into stitch files you can run and source files you can change. Get the stitch format your machine actually reads, get the color list with it because DST won't carry one, and settle the source file question before you pay rather than after. If you'd rather skip all of this, EmbGig designs come machine-ready in the formats people actually use.
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