Pattern drafting in LibreCAD

At the start of the new year I commented about trying to figure out what to do next. I described my feelings as reaching the end of one road and trying to decide which road to take next. You might assume there were only a few options, but in reality there are many. One option was to look at languishing projects to pick back up. I have two rather large projects. One will take me many years, the other is about half done.

The really large project is sodaCAD. I started a software project back in 2010, but let it drop because I lacked the skills to work on it. SodaCAD is my attempt at an open source pattern making software. Most commercial or enterprise level pattern making software packages are very expensive and have onerous maintenance fees and licensing. I've always wanted to provide an alternative.

After much research and a few different attempts, I stumbled upon LibreCAD. LibreCAD is a free alternative to AutoCAD. Commercial pattern making packages have AutoCAD at its core. LibreCAD contains many essential CAD drawing functions already, so it is a perfect foundation to build on. I actually learned how to draft patterns using AutoCAD in college. What I lack is programming skills, but that is slowly coming.

Before I can work on optimizing LibreCAD, I had to test it out and actually try drafting a pattern to test its capabilities. It took a bit of time, but I managed to draft a bodice front.*

LibreCAD is by no means the ideal solution (not yet!) for this kind of work. It is, in many ways better than Adobe Illustrator or Inkscape. Illustrator and Inkscape lack precision and efficiency. Inkscape in particular, tends to be fuzzy when it comes to numbers. Say you draw a square that is 25 x 25, but you move one side out 1 inch. Now you have a rectangle that is 25 x 25.95. LibreCAD has no issues with precision. It does lack efficiency for pattern making, so I made many mental notes for improvement.

LibreCAD is available for use now on Windows, Mac, and Linux. If you do decide to try it out, I would recommend watching some video tutorials on YouTube. The interface and drawing functions take some learning. I have no idea how long it will take to get SodaCAD ready for use.

*This pattern piece is available in sodaCAD source files for demonstration and testing purposes.

Shoulder slope pattern correction

LisaB asked me to explain:

Raise the shoulder at the neckpoint 3/8" on front bodice to correct shoulder slope problem. I need to apply this correction to my t-shirt pattern too.

I tried my first cardigan sample on several times and noticed the shoulder seam was not pointing in the right direction. The seam at the neck point was pointing toward the front rather than laying right on top of my shoulder. I also looked at my t-shirt pattern and observed the same problem. This indicates a possible shoulder slope problem or shoulder to hem length problem on either the front or the back bodice or both. To figure this out, I ran a basting thread in my cardigan shoulder seam area and looked in the mirror to see where I needed to make the adjustment (no fitting buddy or dressform at my house, unfortunately). I also pulled out my blouse pattern and compared the shoulder seam. In the end, I needed to move the shoulder up at the neckpoint 3/8" on the front bodice. This increased the shoulder to hem length on the front just enough to allow the back bodice to relax backward and position the shoulder seam right on top of the shoulder.

Not everyone will need to make this adjustment. This was a problem inherent in my own patterns to fit me. The drawing below, I hope more clearly shows how the shoulder seam was laying.

Adapting a block pattern into something else pt. 8 : the final pattern alterations and a finished design

It took me quite a while to finish up the pattern modifications for this style. I would try on the first sample and look in the mirror, then go back to the pattern many times. There were a few things that were not right. Each time I would try it on, I would pull the jacket forward so the back neck rested higher. This would throw off the shoulder line. Finally, I realized I needed to raise the back neck and raise the shoulder at the neck point on the front bodice. This situated everything nicely. The first jacket is definitely a wearable first muslin, but the second sample turned out great.

Final pattern alterations:

1. Remove extra wearing ease. I noticed that many similar cardigans are not really that much bigger than the average t-shirt, so keep this in mind when adapting your t-shirt pattern.
2. Raise the back neck 3/4". I had left the original neckline of the t-shirt, which ended up being lower than I wanted for the cardigan.
3. Raise the shoulder at the neckpoint 3/8" on front bodice to correct shoulder slope problem. I need to apply this correction to my t-shirt pattern too.
4. Shorten sleeve length.

All that's left is to double check the seams to make sure they match and cut the pattern out of tagboard. This jacket is now ready for further iterations. Maybe a shorter or slimmer version. A waist line with darts. It's all possible.

If I wanted to take this cardigan into production, I already have some of the information needed and recorded in my blank forms:

1. Style and cutting sheet lists all the pattern pieces with spec drawing.
2. Sewing spec lists each step of construction.
3. Fabric swatch cards with content information.
4. Recorded the pieces in the pattern catalog.

To turn this into a more complete spec package, I just need to add:

1. Finished pattern measurements for quality control
2. Grading spec
3. Cost analysis

I've also added a wash testing data form, which is not yet available (soon!) and not included in the book. This form records shrinkage information which is critical for knit fabrics.