This is a great question and has a really fun technical answer! The short answer is that DST files, and some of the other embroidery files are very old file formats. As such, they don’t have the same amount of information in them that the newer embroidery file formats have. Let me explain, this is technical, but pretty fun I think!
In the early days of machine embroidery, embroidery machines were run and controlled by mechanical punch card ‘computers’. A digitizer would sit down and plan out their design on paper, and then hand punch a card corresponding to where they wanted the embroidery’s frame and pantograph to move. The embroidery machine had a complex mechanical way of reading these cards. Since everything was mechanical, there was no electricity for these computers. An operator pumped their foot to make the rotary hook rotate and to read the next line of code.
Each punch on the card meant for the embroidery machine to move in a certain direction. Generally, there were 8 different possible holes per line on the punch card. In computer language, this is referred to as a ‘byte’ of information. 8 individual holes (each hole is called a bit) equaled one line or byte of code. A single punch hard could have hundreds of locations, or X,Y stitch positions.
These bytes could then correspond to special movements of the embroidery machine. Generally two bytes were fed together to get left/right movement and up/down movement. For instance, getting 8 holes in a line could mean 00000000 or move 0 mm to the left. The next line of code could look like 00000001 which meant move 1 mm up.
00000000 (0 movement to the left)
00000001 (1 mm movement up)
The different machine manufacturers each had their own secret code for their embroidery machines. Over the years, it has become very easy to crack some of the initial codes. DST files are some of the oldest, and therefore the easiest for the embroidery machine to run and the most documented. In short, today DST’s are very standard files that, due to their simplicity, run in almost every machine.
Stacks of these punch cards would then be taped together and fed to the machine corresponding to a whole embroidery design. This design could then be reloaded again and again to create the same design perfectly every time. This increased embroidery’s cost and quality and every design was perfectly the same.
As embroidery systems progressed, operators realized that creating punch cards with a hole punch was very hard on the hands and often the card had to be remade due to an operator error. As computers began to become mainstream in the 1980’s, digitizing quickly made the leap to fully digital programs.
A digitizing program could allow a digitizer to create programs far faster than with paper and a punch card alone. In fact, many processes like undoing a mistake previously meant that the whole punch card would have to be punched again. The computer could ‘undo’ the mistake immediately and save paper in the process. Computers for the win!
After the digitizing program created the ‘code’ for the punch card, this data was fed to a punch card maker. This machine looked like a little printer, and would perfectly punch the punch card creating the embroidery machine program.
However, as embroidery machines became more advanced, they became more computerized. Machines were able to create trims, or put sequins down. They could start to be programmed with color changes and multi-needle embroidery machines were born.
As these new embroidery machines began to become adopted, it was clear that an embroidery machine didn’t just move in an X and Y motion anymore, and so an additional punch card contained the ‘header’ information and was taped to the beginning of the embroidery program
Eventually, the file format was updated and new formats were born that had ‘header’ information. This header information contained special codes that could tell the operator what material and colors of thread the machine should be setup with. The header in these new file formats had lots of information in it! This information was used to setup the design so that the machine knew what colors to use.
However, being one of the first adopted file formats, the DST format never really fully updated to this level of advancement. As so, the embroidery machine’s computer ‘randomly’ assigns colors to the design since that information is often not in the header of the program itself.
Ultimately, this is why some of the older embroidery formats and machines require the ‘Chart Information’ which contains the order of color changes as well as the recommended colors for the design. On Kreations By Kara, we freely give out this chart information for every design ahead of purchase so that you can see how big it is, what color threads there, how many stitchers are in the design, and other helpful information before you get started.
In modern embroidery, there are two types of embroidery programs. The first program is the design file. This file is the one we digitizers use and save so that we can modify, size, and change our work. This file can have pictures inside of it as well as notes, color changes, and drawings.
The second file format is the transport code. This is a condensed file format that tells the machine how to run, and is often very similar to the initial punch cards the embroidery machines used to run. Modern machines essentially run on punch card code even to this day!
Hopefully this little bit of history was interesting and helped to explain whey DST files load on the embroidery machine in weird colors while other newer files keep the thread colors.