How to work with an Open Source Sewing pattern

When it comes to creating a carneval costume, sewing is a hard part. Whilst you might find someone with a sewing machine, getting to an appropriate sewing pattern is yet another challange. During our research we came across https://freesewing.org/. It allows you to put your body measures, select a sewing pattern and automatically create a tailor fitted draft. A draft which you then have to transfer to your fabric, cut out and stitch together. As simple as that.
In our case we needed to mount 2000 LEDs and for each LED 4 tiny and one small hole. Therefore we developped a small workflow that works on a small laser, which you might find on a fablab, such as fablab Zürich:  https://zurich.fablab.ch/ 

Ever wanted to be a model? This is the way to start on freesewing.org. Create a model and put your body measures there. These will be used later to create a draft.

On freesweing.org different patterns are available. We prototyped several patterns with different fabrics to fine tune the wrinkles in conjunctions with LED PCB mocks. At the end the pattern of a suit (Jaeger) was the best.
Once you've selected your pattern, you can draft it by choosing a model.

This is the automatically created sewing pattern. For us this served just as a basis and needed some significant rework. Under Download it is possible to get either a PDF or an SVG file.


If you just want to sew a simple costume you need to transfer it to your fabric, maybe on a paper first. The very first drafts we did like this. The final ones were lasered (more below). 
  1. An easy way to bring the pattern to paper was the following
  2. project it on a wall or connect the laptop to a TV screen
  3. adjust the scale by zooming (there is a 10cm scale) 
  4. draw it. 

Easier would of course be to plot it. - but who has a plotter at home? TVs are easier to find ;-)
An easy tool to modify the fabric was QCAD. There is a free version which runs for 15 minutes and then needs to be restared. However we paid for the full version, because it is annoying to restart every 15 minutes and Software Engineering is hard work which needs to be apprecited.
Before you start woking on your pattern, I suggest to read the manual of QCAD it will pay off.
Under file there is a menu which allows to import SVG images. There we imported the SVG from freesweing as a start. 

The typical workflow then looked like this:

  1. create different layers for different elements (e.g. seam allowance. holes, helping ines)
  2. remove unnessary parts (like pockets, ...)
  3. copy and mirror elements (in case your fabric has a different top / buttom structure)
  4. in our case we closed the front and added the holes
  5. make sure, that everything, that needs to be lasered, is on one layer only.
  6. group everything so that it fits on the laser 

Ready to laser? - Not yet!
Before you start the laser, it is recommended to do a couple of tests. We tested several fabric types to see how well the lasers melts together the fibres. As you can see on the white samples some nasty shades can be seen. As well the laser removes some extra material. This can be seen on the black samples, where we actually tried to laser a cross, that now looks like a star.


Once the fabric is selected, laser parameters (speed and energy) must be fine tuned. The perfect way to do this is to laser a small smaple (as the one below) that contains all the final structures. Usually the Fablab Team will find time to support you on tuneing the parameters (thank you for that)

This is how the final parts then look like.

Lasering the parts out with the 5x2000 holes took about 2 hours. Without the holes it would take just minutes.
 Next step is sewing. But there are better webpages for that ;-)