Understanding Distortion

Typically one of the most simple, yet complicated topics in embroidery is Distortion. It seems quite frequently I’m asked why this outline is off, or how come my letters look different sizes? Often this is followed by “It looks perfect in the software”. The Crux of anyone starting out on a digitizing journey is understanding that if it looks good on screen it’s probably not going to look good sewn out. But why is that and what forces are causing this mystical distortion to happen? The reasoning is extremely basic.

Push and Pull

Push and Pull are always the culprit. The basics of which I hope you will understand by the end of this article. Understanding these concepts will set you up to compensate for them in your digitizing so that what you expect to see in a sew out is what you will actually get. To understand this phenomenon we first need to understand the anatomy of a stitch. Our embroidery machines (as complicated as they look) are lock stitch machines. This means that in each stitch hole our upper thread wraps around our bobbin thread and is pulled tight (by the take-up lever). It is when the thread is drawn tight that our battle of push and pull begins.

Pull Happens

This is what occurs when our thread is drawn in. Between the needle points on a stitch as the thread is drawn tight by the take-up lever the holes are pulled together by the thread. If your fabric is under-stabilized it will cause it to buckle under the force and if it’s properly stabilized it will still move, just less. The longer the stitch length the more it will pull as it’s drawn tight. Now this is more of a Yin/Yang type relationship Where you have pull you will always have Push.

Push Happens

Push is what happens to the fabric while the stitch is pulling in. While the stitch points get pulled together the fabric between the two stitches is pushed out the sides. This pushing causes satin stitches to grow slightly in length whereas the Pull makes a satin stitch end up slightly narrower than it’s initial width.


The Magic Formula

Okay, the heading may be misleading. You may have hoped that there would be an instant formula you could use to make all your push/pull problems go away. This is where it becomes much more complicated. Push and pull cause distortion. How much distortion is caused varies between combinations of fabric types, stabilizer types, and machine tensions. But knowing that push and pull will happen allows you to begin to experiment with compensation since you know what you are attempting to compensate for. Often when I see questions regarding distortion the answer is usually “Add Pull comp” which not always will correct the issue, but will in most cases help. The lack of explanation makes it difficult for people to understand what exactly they are compensating for. Me telling you “It’s pulling” doesn’t really tell you why it’s pulling, or what forces are at play.

Measuring Distortion

This is by FAR my favorite exercise and it’s so simple everyone can do it! When your having issues with distortion you can simply measure your sew out and compare the dimensions you have in your software!!!

The difference: distortion caused by push and pull.

The remedy: adjusting the dimensions to compensate the distortion and give you the expected outcome. Really I’m saying “Test, Measure, Analyze, Change, Repeat”.

Testing

Have you ever wondered how someone became good at digitizing? What about how much push/pull compensation to add to get a baseline of text to line up? Experience, Digitizing, Testing, Analyzing, and Repeating.

I test every design I do. This means to stitch out every single one on as close of fabric and stabilizer that I will be using for my final project. Never be afraid to move nodes to line up a fill and a outline. After doing these tests for a while you will get a feel for how much you need to compensate for a particular application. Of course, as always, if your struggling you can always ask for help. I have found though that people are a lot more willing to help someone who has tried and is having trouble than someone who hasn’t tried at all. Embroidery is as much about art as it is physics, learning to master it takes time, dedication, patience and practice. Hopefully if you have made it this far you understand the forces causing your distortion and I have given you ides to compensate for it. I do offer these words of encouragement. It will get easier… Then harder… Then easier again. The fun in being experienced is the experience to get you there.