Why is My Bobbin Thread Showing on Top of My Embroidery?

The root cause of bobbin thread showing on the top side of machine embroidery is tension. Your job as an embroidery detective is to determine what’s causing the tension problem so you can avoid tension headaches. Learn common causes and their solutions!

Understanding Thread Tension

With machine embroidery, we don’t want an evenly balanced tension that is optimal for “normal” sewing. Instead, we want the bobbin thread to pull the top thread to the back. 

With machine embroidery, we don’t want an evenly balanced tension that is optimal for “normal” sewing. Instead, we want the bobbin thread to pull the top thread to the back. 

If you imagine the needle thread and bobbin thread as having a tug of war, the stronger one will pull the other one to its side.

If the bobbin thread is on top, that means the top thread is pulling more, or, has more tension. That means either the top thread is too tight or the bobbin thread is too loose. 

Factors That Affect Tension

Obviously, machine settings are the first thing that come to mind. Most home machines have automatic adjustments that occur when you switch into embroidery mode. Some machines also use a different bobbin for machine embroidery.

The next major factor that affects tensions is thread weight and that includes both top and bottom. Along with weight is the texture of the thread. We’ll just focus on weight here.

Thicker threads increase tension and thinner threads decrease tension. If you use a thicker thread in the needle, you may get more bobbin thread on top. If you use a finer thread in the needle, then you might see relatively little bobbin thread on the back in satin columns.

Stitch length also affects tension. Longer stitches tend to be fluffier and are more likely to loop (some machines are worse at controlling looping than others). Short stitches tend to be pulled more tightly into the fabric and are also more likely to pull the bobbin to the top.

Become a Detective

First, determine if the issue is fairly consistent or just a random here and there thing. Does it happen with certain stitch types or certain threads? 

Occasional Occurrences

If it’s just an occasional, random occurrence, then it’s likely due to a momentary upper thread feed issue. The top thread may have caught on something. Common places for this are:

  • A slit or rough spot on the spool
  • The thread has slid off the bottom of the spool/cone/tube and pooled underneath and is now hung up (can also cause thread breaks)
  • The thread has tangled and hit an obstacle, such as a thread guide

Look for these types of issues and try rethreading the upper thread. Another solution is to extend the thread path to allow the thread to relax and unkink before it gets to the first thread guide.

Most embroidery threads are cross-wound and these are designed for the thread to feed off the top of the spool. 

I prefer to use some kind of thread holder that allows for a longer thread path. Some machines have an optional platform you can attach. Or, you may need to get some additional device. Some that I use (and appear to be discontinued at this time) are the Echidna multi-spool thread stand and the Hemingworth Control-A-Twist thread stand (both shown here).

Some alternatives to these are listed at the end of this post.

Consistent Occurrences

If the problem is more consistent, then you may need to adjust some tension settings or possibly just to a little housekeeping. 

Common causes for consistent problems are:

  • Improperly threaded machine (top and/or bobbin)
  • Dirty bobbin case
  • Incorrect bobbin or bobbin case used
  • Change in bobbin thread type (weight, brand, fiber type)
  • Damaged needle

Before you adjust any tensions, attend to routine maintenance. When was the last time you cleaned out your bobbin case and bobbin area? 

A good habit to get into is to clean that area out each time you change the bobbin. Some fabrics and thread types contribute to fuzz more than others and you will definitely need to clean more after those. Even the tiniest bit of fuzz in the bobbin tensioners can open it up enough to result in the bobbin thread flowing too freely. 

  • TIP: Check your manual for how to thoroughly disassemble the bobbin case area.

Use a soft brush to clean out the area of any lint, fuzz or threads.

Do not use canned air as you could blow crud deeper into your machine. A good investment is a set of small attachments for vacuuming snug spaces.

Sliding a business card through the tension discs on the bobbin case works well. Avoid using a pin or needle that could possibly scratch the bobbin case and contribute to thread damage.

Drop-in bobbin.

Front-loading bobbin.

Next, make sure you are using the recommend bobbin type and weight for your machine. Some machines work well with pre-wound bobbins, others not so much. If you are using prewounds, make sure they are the right size. A size L and class 15 bobbins are the same diameter but different heights and are therefore not interchangeable.

If you’re winding your own bobbins, make sure they are wound evenly, with neutral tension, and not over-filled.

  • TIP: Check your manual. For example, your machine may have come with a specific brand of bobbin thread and your bobbin may be factory tensioned to work with just that one. The smoothness and weight play a huge role in how the thread passes through the bobbin tensioners.

This is not to say you can’t use a different type of bobbin thread. It just means you may need to adjust your bobbin tension for proper tensions.

Adjusting the Bobbin Tension

Even if you’re using all the same types of threads that worked before, you’ve cleaned your machine, have a new embroidery needle, and know everything is threaded correctly, you may still need to adjust your bobbin tension. Why? It will just lose tension over time. Although bobbin cases are designed for long use, they are still considered disposable.

Some machines will come with two bobbin cases. One may be specifically designated for machine embroidery. Lower end models may only come with one bobbin case and the adjusting screw may be covered to prevent any adjusting. It’s smart to have a second bobbin case that you use just for embroidery. 

To adjust the bobbin case, turn the tension screw in no more than 1/4 of a turn using the guideline “righty tighty, lefty loosey.” If the bobbin thread is showing on top, you’ll want it tighter. The only way to know if you adjusted correctly is to test sew.

Adjusting a drop-in bobbin case.

Adjusting a front-loading bobbin.

How to Measure Thread Tensions

Pros often use gadgets to measure bobbin and thread tensions. Digital gauges can be cost-prohibitive so you might want to consider simpler tools, such as this Echidna Thread Tension Gauge.

Types of Bobbin Cases

Currently, there are two ways machines handle bobbins:

  • Drop-in
  • Front-loading (“push-in”)

I cover both of these in my ebook, The Embroidery Recipe and won’t go into how to thoroughly clean or adjust them here.

How to Test Tension Adjustments

The standard test for verifying tensions is to sew a 1″ tall satin stitch block capital “H” and check the backside. You should see the bobbin thread running down the center and approximately 1/3 of the total column width with 1/3 needle thread showing along each outer edge.

What Tension Problems Are Not

While long and short stitches do have an effect on how tightly a stitch is formed, I know of no way to make a design that intentionally causes bobbin thread to come to the top or other tension issues. 

How a design is digitized can definitely contribute to puckering, warping, and registration problems. And those issues can be controlled or exacerbated by your choices and techniques. (See other blog posts or download The Embroidery Recipe for a more convenient resource.)

What To Do If Nothing Works

If none of these tips work for you, it may be time for some machine servicing. You should be scheduling regular maintenance with a qualified service technician to keep your machine in top working order. Be sure to provide the service department with samples along with details such as threads and needles used.

Where to Learn More

Machine embroidery can look deceptively easy. But the more stitch-outs you do, the more you realize you need to know. Why is this happening? What caused that? Why did it work well last time but not now? What stabilizer should I use?

If you want to become a better embroiderer, check out my two books:

These are both PDF books that you can download instantly. PDFs are easily searchable and can be at your fingertips on your computer or mobile device. They are printable if you prefer a hard copy. The Embroidery Recipe is available in printed form from Amazon.

The Embroidery Recipe: How Your Ingredients Affect Your Results

This book is designed for all embroiderers, no matter your skill level or what type of machine you have.

It covers all aspects of the embroidery process and includes many helpful troubleshooting charts. If you have a question about embroidery, it’s most likely covered in this comprehensive book.

Anatomy of a Design: How to Think Like a Digitizer and Become a Better Embroiderer

Anatomy of a Design ebook image

This book is designed for a more experienced embroiderer and is designed to help you understand more about how designs are constructed.

Once you know the secrets of what goes on under the hood of an embroidery design, you’ll have a better understanding of how it will sew on various fabrics. You’ll also be able to look at a design in software and see what issues you might be facing and even if it’s worth sewing at all.

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