Design + Digitizing
How to Work With Push-Pull Compensation
Digitize to work with your embroidery machine rather than using compensations or corrections that have been built into digitizing software programs.
June 25, 2013
There are two great mysteries that digitizers must solve to build the perfect design: underlay and push-pull compensation. The greatest of those mysteries is push-pull compensation. Once solved, the second mystery, underlay, will fall into place.
Let’s talk about compensation. Webster’s Unabridged Dictionary defines the word “compensate” in the following manner: “to counter balance, to offset, to make up for or to adjust.” I think it is easiest to define compensation as “correction.” I also think that, as professionals, we should work toward not having to correct our designs.
Let’s start with some insight into push-pull compensation. The fact that stitches tend to pull in while pushing out has been at the heart of costly industry research. The compensations or corrections have been built into all of our digitizing software programs. However, with all the money spent on correcting the problem through compensation, very little has been spent on analyzing what causes it and how to digitize in such a way that it does not occur.
Of the adjustments or corrections available in software programs, some are good and some are bad. However, all are confusing, none are 100% effective and none give you the ideal design. Most corrections suggest heavy underlays that hold the garment in place, or purposely distorting the design so it will pull in on the sides just enough to push out at the top to perfectly fill the area. Learning the correct underlay and formula for the distortion is confusing and close to impossible. If you are lucky, the corrections will work. Sometimes.
But what happens to the fabric as it is pulled in? Have you ever pulled material in at a 45-degree angle? The material stretches, so it becomes compact and tends to pucker. The resulting product — with stitches compacting, underlying material pulled in and heavy underlay included — is a heavy patch of color with thread packed in so tightly that it distorts anything on top and does not look like part of the garment.
Think how easy it would be if there were no push-pull phenomenon that needed compensation. How nice would it be to look at the image on the screen and know that is what you will get in your sewout. Without the distortion, you will see any flaw that you may have made — and any flaw you see can be corrected before you stitch the design.
This means, as a professional digitizer, you will only have to proof your design once, not several times. You won’t have to tweak it, stitch it out and tweak it again.
THE PERFECT DESIGN
Let’s take the traditional formula that we have examined and its push-pull problems, and replace it with one that is easy to understand, makes sense and will give you results you can count on.
The perfect design should move with the garment, be subtle and pliable, and look like it is part of the garment. Ideally, we must add detail or stitches on top of the fill patterns without interference from the underlying stitches. The finished design should work on all fabrics without making drastic changes, and scale up and down easily. It should run well with no thread breaks, and it should have just enough stitches to cover the material and give it the true and consistent color that is prescribed.
Our background fills (or tatamis) should be just that — backgrounds. They should work as a platform to show off and enhance the important detail. You should be able to lay the background stitches down in such a way that anything may be placed on top with no interference. To do all of this, we cannot use the standard pull compensation formulas. We need to address the direction, density and length of the stitches, as well as underlay.
When you try to control your machine through compensating, the heavy stitches applied to your material fight for room on the garment. Instead of correcting the problem, they are, in fact, causing it.
However, if you place a light density fill on the garment as an underlay, it will not pull in, nor will it push out. If you add a second layer, it also will not pull in. A third layer, again, will not add to the stitches in such a way as to distort your image and will not pull in. So if you layer your fills instead of putting all of the stitches down at once, you will find that there is no pulling, pushing or distortion, yet you still will have full coverage.
BUILDING THE LAYERS
To build layers, we will start with a 1⁄3 density fill, the same fill that we used for our blending and shading techniques (see March and April/May 2013 issues of Impressions). Start by creating a square inch of fill. Make sure no underlay is present. With a stitch length of about 3.5 or .35, depending on your software, and the density at default, my computer tells me 1 square inch contains 939 stitches. One-third of that density is about 300 stitches per inch.
Check the density setting on your computer when you reach 1⁄3 of the stitches. This is the density you will use when layering objects in your design.
That 33% density is not much heavier than an underlay. And, as we found with the blending technique, by running the layers in the same direction (the same angle) they will blend together and your stitches will not fight for room.
Because you cannot physically put a stitch on top of another stitch, the needle finds the void in the underlying layer and places the new stitch in the open area. As you add each layer of your fill, the stitches will be placed by the embroidery machine in such a way that they fall naturally in place. Thus, you will not be fighting the machine; instead, you will be working with it.
Create a circle with this light density fill. Your stitches will start at the top, go horizontally and finish at the bottom. If you then take a running stitch and outline the circle, you will see that there is no distortion when you stitch out the design. The fill will line up with that running stitch outline.
Using the original circle, create a second circle of the fill pattern by duplicating the first layer of fill. Add an edge-walk underlay or a running stitch outline under the second layer, and stitch that on top of the first layer. There still will be no pull, pushing or distortion.
As this second layer is an exact duplication of the first, move your start point to the bottom where you finished your first layer, then move your stop to the top.
After putting down two layers that add up to a little more than 65% density on your garment, you may add a final layer by duplicating that first layer again and adding it on top of the first two layers. Now, with three layers and 100% coverage, you have a perfect circle. It is one that looks like a circle on your screen, and one that will stitch out as a circle on your machine.
You will have no distortion or thread breaks, and you will have room to add lettering and detail. Also, the image will drape with the fabric and you will have the perfect design — one that can be scaled easily and works on almost every kind of fabric. It is one that needs only the simple running stitch as an underlay to keep its edges clean, and one that has not built in a “correction.”
By using enough stitches to give you full coverage and laying them down gradually, there is no torque or pulling and very little need for underlay. Also by placing one light layer, then adding a second and a third, you will find that even in a light density fill, the needle of your machine will be deflected to a void area and will not place a stitch on top of a stitch.
This is a simple exercise to try, and an answer to the problem of push-pull compensation and underlay. This technique does not leave your resulting design to chance or luck. You are working with the machine; you are not trying to force the machine to do something that it physically will not do. By doing this, you will find you are successful 100% of the time and that your sewout is not only attractive, but also runs well. As an added bonus, you now have created the structure that will hold your column stitch or satin stitch in place if you are adding it to your circle.
Lee Caroselli-Barnes, owner of Balboa Threadworks Embroidery Design, is known for her innovation and excellence in embroidery digitizing. She has 30 years of experience in the embroidery industry. For more information or to comment on this article, email Lee at firstname.lastname@example.org. Hear Lee speak on digitizing topics at the 2013 Imprinted Sportswear Shows (ISS). Individual seminars are just $25 if you preregister: issshows.com.