There are a number of causes for puckering and often a combination of reasons that contribute to that unsightly effect in a particular sample.
A roundup of the usual suspects includes:
- A high distortion factor design
- Inadequately stabilized goods
- Fabric that was stretched during the hooping process
- Overly tight machine tensions, especially when combined with polyester thread and high sewing speeds
- Thread displacement
We’ll look at each one these so that you can learn to predict a potential puckery problem and take a little preventive action.
High Distortion Factor Design
If you have a design with a relatively high stitch count for its size combined with multiple varying stitch directions and layers of shading or other details and objects, you have what I call a high impact design. Contrast that with say a redwork design, a monogram, or a typical appliqué, which are lower stitch counts with more open areas of fabric around and within the design.
Think about aerobics classes. When these exercise classes first became popular, they involved a lot of jumping, hopping, kicking, arm flailing, and panting. Later, as some of the negative effects of this stress on the body became apparent, the movements were toned down and we began seeing “low impact” aerobics. (By the way, if you want to firm up and loose weight, aerobics classes are not the best option… but that’s another topic entirely!)
In the same way that high impact aerobics stresses the body more, high impact embroidery stresses the fabric more. The needle is stabbing the fabric with a potentially lethal weapon. (If you don’t believe me, sew through your finger a time or two!) Higher stitch counts mean more thread is being forced between the fibers of the fabric. The action of the needle and bobbin threads forming stitches creates tension and pull on the fabric. When a design has stitches running at many different angles relative to the fabric—particularly if those stitches are fills—the fabric can be pushed and pulled in a variety of directions.
Inadequately Stabilized Fabric
Most items we embroider stretch to some degree. The more a fabric stretches the less stable it is. Stabilizers are products that may be placed behind the fabric (backings), over the fabric (toppings), or applied to the fabric (starch, temporary spray adhesives). The hoop is a critical part of the stabilizing formula. Fabrics that are hooped between the rings of the hoop along with the backing, especially if the stabilizer has been further secured to the fabric with an adhesive, are more secure and stable than “hoopless” embroidery in which the fabric is attached to a stabilizer that is hooped or adhered to the hoop. The higher the design’s distortion factor and the more unstable the fabric is, the more the item must be augmented to provide suitable results. Additionally, a high distortion design is more likely to cause the fabric to slip in the hoop resulting in an additional problem where areas of the design become misregistered.
Stretched Fabric During Hooping
Unless you are sewing on Lycra or similar fabric that is worn stretched across the body, fabric should be in a neutral position in the hoop. That means the fabric should be smoothly hooped and not stretched or distorted in any way. If you pull on the fabric after hooping, you are stretching it! After embroidering, the fabric will relax back to its normal state and voila! puckers. In the case of Lycra, the goal is to stretch it to the point it will be worn on the body for a smooth embroidered finish. Yes, it will look hideous hanging on the hanger but we really only care how it looks hanging or stretched on the body.
Tensions, Polyester Thread, and Speed
The tighter the needle and bobbin thread tensions on the machine, the more pull there is on the stitches thus resulting in more distortion. And, as your machine speeds up those tensions increase. As tensions increase, thread is stretched and pulled tighter and tighter. Polyester thread will stretch to a point before it breaks. This thread has as one of its attributes a thing called “recovery.” You can think of this as having a memory of its natural relaxed state. Over the 24 hours after sewing and removing from the hoop, it will attempt to return to that state. In other words, after being stretched during the sewing process it will “shrink,” producing—you guessed it—wrinkles and puckers around the embroidery.
The only difference between these two designs is that the one on the left was sewn with rayon thread and the one on the right with polyester. This sample was sewn on a home machine at the default tensions. Each rose was sewn separately under ideal conditions (except for adjusting the tensions).
Compare the close-ups of the rose below and notice not only the wrinkles but the how far off the outline is.
View of tensions on the back:
In my opinion, most home embroidery machines are tensioned too tightly for embroidery. Also, a lot of commercial embroiderers set their tensions too tightly. You may be thinking, “I ran a test, my tensions are balanced.” Tensions can be balanced but still too tight. Every time the tech comes to service my SWF, I have to readjust the tensions after he leaves to create a softer stitch. The best tensions I’ve ever seen are on the Babylock and Brother 6 needle machines.
If you have a home machine, your dealer may have sternly warned you about altering the tension screw on the bobbin case. Get a second bobbin case and adjust it as needed, reserving it for embroidery. Learn to modify the upper thread tensions, which may be a knob or may be done through your machine’s software.
This is an often over looked reason for puckering. While we talk about embroidery on an item, we are technically embroidering through it. Each needle penetration except the first and last has two pieces of thread in it—one going in and the second coming back out after the bobbin thread has been picked up. That thread requires space. The more tightly woven a fabric is, the less breathing room there is between fibers, leaving little or no space to accommodate this extra thread.
The fabric fibers are pushed apart for the embroidery thread. The fabric has to go somewhere and at some point, wrinkles, puckers, and cupping result. Proper stabilizing can reduce this effect, but only to a degree.
To further illustrate this, imagine you’re filling the bathtub for a nice soak and you’ve let the water run to within a few inches of the rim. As you sink into the water, the higher the level of the water raises. If you displace enough water, the tub can overflow. This is exactly what is happening with the thread and the fabric.
We often think of denim as a very stable fabric that will support embroidery well; it will to some degree. Watch out for denim that has Lycra woven it; it is designed to stretch a bit for a better body hugging fit. Here’s another thing to think about concerning denim. Even if your denim jeans are not laced with Lycra, think about how tight they are coming fresh out the dryer but then a few hours later they have “relaxed.” Do you really think you became smaller or did your jeans stretch?
Another popular yet problematic fabric is microfiber. Microfiber refers to synthetic fibers that measure less one denier, about 0.7 denier. To give you a clue how fine this is, 9,000 yards (a little over 5 miles) of a one-denier fiber weighs one gram or roughly .035 ounces. Microfiber fabrics are typically very tightly woven and are generally much lighter and softer than denim. These qualities are ideal for puckering so use extra care when selecting designs for these fabrics.
There will be some cases where you just can’t eliminate every pucker and ripple. Unfortunately, once you have puckers, for the most part they are permanent. Here is a list of best practices:
- Prepare the fabric by preshrinking it. If your fabric shrinks after the embroidery is applied, all your efforts beforehand are for naught.
- Provide the best possible match between fabric and design. If that design must be sewn on that fabric, can you reduce the design’s density? Run the design through Density Works or similar program to look for areas that can be improved.
- Can you offset distortions with stabilizers or starch? Try using adhesives with your backing (I prefer sprays or double-stick embroidery tape rather than sticky backings.) My favorite stabilizer is fusible no-show mesh.
- Make sure you pay close attention to hooping—fabric should be in a neutral position and not slip at all during the sewing process. Use a hooping aid or duct tape to make sure slippage can’t occur. (Tear lengths of tape in half lengthwise and wrap around hoop onto backing as shown to the right –>)
- Baste your design to the stabilizer before starting the design. Some machines have a built-in feature or use software to add a basting stitch before sending the design to the machine. Convert It Mac and Color It will do this for you effortlessly.
- Optimize your tensions by using a tension gauge. Make sure your tensions are comfortably loose and balanced. A little bit goes a long way here! When adjusting the bobbin, try an 1/8 of a turn at a time. If tensions are too light, looping will occur.
- Slow down the sewing speed.
- Switch to rayon thread.
- Use the finest (smallest) needle that can penetrate the fabric without damaging the fabric, thread, or allowing the needle to flex. This is a good rule to follow any time but pay particular attention when pucker prevention is paramount. Using a sharp needle with tightly woven fabrics can also reduce puckering. Embroidery needles are slightly rounded (somewhere between a sharp and a ballpoint).
- When in doubt, appliqué! Just joking, but only halfway. Appliqués work on a wider range of fabrics than full stitch designs but that’s a subject for another article!