How DST files work and the Limitations
Embroidery enthusiasts in various Facebook groups and online forums where individuals of all skill levels often have a few questions about the use of DST files. One question that frequently arises from newcomers is, “Why doesn’t my expensive embroidery machine and software communicate effectively and send the correct colors using a DST file?” Another question is “Why does my design come out bad when I resize it?” Frustrations like those are just two of many that we aim to address.
We understand your frustration. Whether you’ve invested over $10,000 in a professional embroidery machine or a few hundred dollars in a home-level setup, it’s perplexing that, in 2023, you still have to input color changes manually, often using lengthy numerical sequences. This becomes even more exasperating when working on designs that require numerous revisions, each involving over 50 color changes. A single typo can lead to a ruined embroidery project, not to mention the potential damage to expensive customer garments.
The simple explanation for this issue lies in the limitations of the DST (Data Stitch Tajima) file format, which, in most cases, cannot support color change codes. Yes, there are rare situations where DST files can convey color information to the embroidery machine, but experiencing such a perfect compatibility is indeed a stroke of luck.
The problem with file formats like DST (PES, EXP, JEF, and others) used by embroidery machines is their role in converting software-generated code into hardware-level instructions. While various machines accept different file types, we will focus on the most popular format, DST. Unfortunately, DST files are incapable of storing images or vectors required for artwork and complex patterns.
DST vs. EMB
You may have wondered why you can’t simply transfer a Wilcom .emb file or a .be file from Embrilliance directly to your embroidery machine. The straightforward answer is that .emb and .be files are Native Working Files specific to particular embroidery software. These files store additional data that DST files cannot accommodate. Software like Wilcom, Pulse DGML, Floriani, Embrilliance, Chroma, and others provide advanced tools for creating intricate patterns, curved fills, satin shapes, and text. However, embroidery machines do not understand native file formats because the machines use Machine Formatted Files to understand in a universal language what actions or movements to make.
There are also other limitations that users frequently inquire about, such as resizing a design. If you’ve ever attempted to enlarge a DST design from a small patch to a large jacket-sized embroidery, you may have noticed a significant loss of quality. This discrepancy is related to how DST files register points compared to native files.
In native files, when you enlarge an object, the software calculates new needle points and adds them accordingly. For instance, if you have a straight run stitch that’s originally 6cm long with a 2mm stitch length, the software computes 30 needle points. If you enlarge it to 8cm with a 2mm stitch length, you now have 40 needle points, maintaining quality and accuracy.
Why the Different Native Working File Types?
One reason for the existence of various native working file types is rooted in U.S. copyright law. However, there isn’t a law mandating that DST and EMB files must be incompatible. Instead, the law governs the ability to copyright a file format. Software developers like Wilcom and Tajima invest significant resources in creating and updating their software with new features. To remain competitive and protect their work, they want to secure their files, preventing other companies from simply copying their innovations and stealing their customers. Trust me, this is a good thing.
Under U.S. law, filing for copyright protection of a file format is not allowed. This prevents a company from monopolizing all top-level file formats and forcing new entrants to use convoluted file names. Imagine creating digitizing software named “Tin Can Digitizing Software” and having to use filenames like “sunflowerpatch.tin392” because all sensible options are taken. That would be chaotic. At the same time, this prevents Wilcom from registering every possible three letter file extension (.xxx) and forcing someone to use long file names. In fact, most machines have a limit on the length of the file name!
What companies can do, however, is encrypt their files using proprietary methods that can be patented. This encryption prevents other software from opening these files. While Wilcom is a prominent user of .emb files, anyone can develop software that uses .emb files legally, which is why almost all digitizing software can export to the open and unprotected DST format. It would be illegal to write software that can take a Wilcom .emb file and manipulate it by hacking the file.
The DNA for the Data Stitch Tajima (DST) File
If you’ve ever opened a DST file with a basic text editor like Notepad, you’ll find plain text followed by seemingly incomprehensible gibberish. This gibberish forms the machine logic that instructs the embroidery machine.
DST files can only contain stitch commands and basic metadata for the design file. When you load a DST file onto your machine or view it on your machine’s screen, you’ll typically see basic information such as the design name, stitch count, and perhaps color change notifications. Occasionally, you may also see author details, copyright information, and listed thread colors, although these are not common.
In the screenshot on the right, you’ll notice line numbers on the left, ranging from 1 to 13. These numbers indicate the line of the file, known to programmers as the “header.” Based on this, we can infer that this section is the beginning of the file.
The header contains specific design information that appears on your machine when you load the file. For example, on line 1, you’ll see “LA:Design42,” which represents the design’s name. The “ST” line provides the total stitch count for this design, “CO” denotes the number of color changes, and the other values pertain to positioning and determining the design’s size for hoop compatibility.
However, you’ll notice that there is no line in the header for specifying the color sequence. This is why you can’t directly instruct the machine about color changes from your embroidery software using a DST file.
So why Use DST?
The primary reason for continuing to use DST files is their universal compatibility with almost all commercial embroidery machines. You can be confident that almost any file you receive from your digitizer (See who we recommend) will work seamlessly on your machine, ensuring consistent results.
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