Original text by: Lisa Prass
Once an idea came into my head — to change the size of the digitized machine embroidery design, which I have downloaded from one of the numerous machine embroidery design websites. Having loaded the design file into the machine, I resized it and pressed the Start button. Imagine my surprise when I noticed that the result differed greatly from the one I saw on the screen. I began to investigate this problem presented and arrived to a conclusion that it's better not to change the size of a design created with the use of the other software...
Changing the size of a digitized embroidery design: From the creator to the embroidery machine
Each machine embroidery design has its creator (puncher), a designer who creates a file using machine embroidery software. The name of this software is sometimes known only to the designer himself.
After the job is finished, the designer saves the embroidery design file in the special format, which is recognized by this software in case there is a necessity to resize the design or change the stitching sequence — in other words, to edit the file. Having decided to share his invention with people, the creator converts the file into various formats recognized by embroidery machines of various brands (*.HUS, *.PES, *.JEF, *.ART etc.).
And so this embroidery design fall into the hands of a demanding customer who wants to change its size and gets a result completely opposite to what is expected. If the spacing between the stitches becomes too narrow, all those beautiful filling patterns become flat or disappear completely. To understand why it happens one should look into the interior arrangement of a digitized machine embroidery design file.
The Inner Structure
A digitized machine embroidery design file is basically a series of stitches together with special codes understood by embroidery machines.
All file formats fall into one of the two categories: stitch formats and outline formats.
Outline formats retain the detailed information not only about stitches and machine commands, such as Trim, Jump or Color Change, but also about fillings, object outlines and the instruments that created the design.
We call this a "native file format". You can resize a design like that with no loss in quality using only the software in which it was created.
Usually, the outline file remains in the designer's collection, while the stitch file is the one that is shared with the public.
Stitch file only retains the stitch data and machine codes. All the details referring to object outlines and fillings are deleted from this file. A stitch file exist solely for the purpose of loading it into the embroidery machine and embroidering.
But as different embroidery software tools as well as different embroidery machines use their own "languages", the native outline file of one software program will be recognized as a stitch file by the other or not recognized at all, if there is no such option available.
Changing the size
You can change the size of a design using software for creation of digitized machine embroidery designs or convertor software or the embroidery machine itself, if it has such an option.
First, I want to point out that changing the size of an already digitized design is a thankless job and one should avoid it whenever possible.
But it you are determined to make a ready-to-use design smaller, here are two ways of doing it:
1. Changing the size of a digitized embroidery design by re-calculating the number of stitches.
Most of the software products for creation of machine embroidery designs have the object recognition option. In fact, this process may be called tracing from the stitch format into the outline one. If you are familiar with image editors, this process is similar to image tracing, i.e. converting a raster-based image into a vector-based one.
When loading the design into the software or changing it's size the user can use the option of object recognition and in this case the software will try to single out a group of stitches which, in its opinion, resembles an object created with the help of available tools.
I should point out that there is no contemporary embroidery design digitizing software that can fully recognize objects and recreate all the filling patterns. You will either get an object with wrong filling pattern or an object where the stitches are distorted.
Such objects as straight stitch, satin stitch columns with the invariable stitch length are recognized better than the others.
The objects that pose problems are the ones of an intricate shape with complex filling, made with alternate needle points, also satin stitch columns with different stitch lengths.
2. Changing the size of a digitized embroidery design without re-calculating the number of stitches.
The process of resizing a design without re-calculating the number of stitches is very similar to changing the map scale.
Remember your geography lessons. The map on the wall was much bigger than the outline map on your desk.
The distance between cities is similar to the spacing between the stitches in a design (we call it density). Making a design bigger or smaller, you change spacing proportionally.
When resizing a design without re-calculating the number of stitches you risk getting a design with not enough space between the stitches or too much space between the too long stitches. This happens because the program sees the design as the plain stitch with different spaces between stitches.
This method is useful when the density of the chosen design doesn't suit you for some reasons, and you want to change it whereas making the design 5-10% bigger or smaller is OK with you.
While changing the size of a design in that way don't forget to register the appearance of minimum and maximum stitches.
Change the design size for no more than 5-10%.
Consider that PES format is marked both as stitch and outline. Almost all software programs recognize it as stitch, and only PE Design considers it outline. But here's the nuance to it: a PES file must be created in PE Design, not converted into it in other software.
EMB is an outline file, a native format of Wilcom software. It doesn't have any relevance to EMB stitch format, which is recognized by Pfaff embroidery machine.