What Weight Bobbin Thread For Machine Embroidery

Getting your bobbin thread weight right is essential for smooth stitching in machine embroidery. It’s a common question: what weight bobbin thread for machine embroidery should you use? Think of it like setting the foundation for a workout. If your base isn’t stable, everything on top will suffer. The same goes for your embroidery. The bobbin thread works underneath, supporting the decorative top thread. When it’s balanced correctly, you get beautiful, smooth stitches every time.

So, let’s get straight to the point. The most common and recommended weight for machine embroidery bobbin thread is 60 weight. This fine, lightweight thread is the go-to for a reason. It creates less bulk on the back of your design, which is crucial. A bulky back can cause puckering and tension problems. Using a 60-weight thread in the bobbin allows the top thread to pull it to the middle of the fabric sandwich neatly. This creates that perfect lockstitch without adding unnecessary volume.

You might also see 60-weight referred to as #60 or even 60/2 or 60/3. The second number refers to the ply. Both 2-ply and 3-ply options work well, but 3-ply is a bit stronger. For most projects, a good quality 60-weight, 2-ply pre-wound bobbin is a fantastic choice. It saves you time and ensures consistency.

Why Thread Weight Matters in Your Bobbin

Using the correct thread weight isn’t just a suggestion; it’s a core principle for success. Here’s why it makes such a big difference:

Tension Balance: Your machine’s tension dial controls the top thread. The bobbin tension is usually set with a small screw. A heavier bobbin thread (like 40-weight) requires more tension to pull it up. This can throw the whole system off, leading to loops on the top or bottom of your fabric.
Reduced Bulk: Embroidery designs have many stitches close together. A thick bobbin thread fills up the bobbin case area quickly and creates a lumpy back. This can make your fabric pucker and even cause your needle to break if it hits a thick thread nest.
Smoother Operation: A fine bobbin thread feeds more evenly from the bobbin case. This results in consistent stitch formation and less thread breakage. It helps your machine run smoother, just like proper form helps you lift weights safely.
Better Coverage: With the bulk managed on the back, the top stitches can lay flat and smooth. This gives you the crisp, full coverage you’re aiming for in your designs.

When to Use a Different Bobbin Thread Weight

While 60-weight is the standard, there are exceptions to every rule. Just like you might adjust a workout for a specific goal, you adjust your thread for specific projects.

Heavy-Duty or Metallic Top Threads: If you’re using a tricky 30-weight or a metallic thread on top, you might need a stronger bobbin. In this case, switching to a 40-weight bobbin thread can provide better balance and prevent the top thread from breaking the finer bobbin thread.
Specific Thread Brand Systems: Some thread companies, like Isacord, often recomend using their 40-weight thread in both the needle and the bobbin. This is a system approach, and it works well if you use all their products together. Always check your thread manufacturer’s guidance.
Decorative Bobbin Work: This is a special technique where the bobbin thread becomes the design on top of the fabric. For this, you’d use a decorative thread (like a heavy rayon or wooly nylon) in the bobbin and a plain thread on top. The weight here is chosen for visual effect, not for hiding.

Step-by-Step: Setting Up Your Bobbin for Success

Getting the right weight thread is only half the battle. You need to handle it correctly. Follow these steps for a perfect setup.

Choose Your Thread: Start with a quality 60-weight polyester bobbin thread. Polyester is strong and has a bit of stretch, which is ideal for the high speeds of embroidery.
Pre-Wound vs. Self-Wound: Pre-wound bobbins are incredibly convenient and consistent. They are wound perfectly tight on paper bobbins. If you wind your own, use a slow speed and ensure the thread feeds evenly onto the bobbin. An unevenly wound bobbin will cause tension headaches.
Insert the Bobbin Correctly: Follow your machine manual’s diagram exactly. The thread must come off the bobbin in the correct direction (usually counter-clockwise for most drop-in styles). Getting this wrong is a common source of thread breaks.
Pull the Thread Under the Tension Spring: After inserting, pull the thread tail until you feel it click into the tension spring. You should feel a slight resistance. This step engages the bobbin tension mechanism.
Do a Tension Test: Run a test embroidery on a scrap of your actual project fabric with two layers of stabilizer. Look at the back. The bobbin thread should be slightly visible in the middle of the stitch, but not dominating. If you see loops on top, your bobbin tension might be too loose. If the bobbin thread is pulled tight to the top, it’s too tight.

Common Bobbin Thread Problems and Fixes

Even with the right weight, things can go wrong. Here’s how to troubleshoot like a pro.

Bird’s Nests on the Bottom: This messy tangle usually means the top thread is not correctly threaded, the needle is damaged, or the bobbin is in wrong. Re-thread everything from the start.
Bobbin Thread Showing on Top: If the bobbin thread is peeking through to the right side, your top tension is likely too loose. Try increasing the top tension slightly first before adjusting the bobbin.
Thread Breaks Frequently: Check for nicks in the bobbin case or the needle plate. A rough spot will shred fine thread. Also, ensure you’re using the right size needle for your top thread.
Puckering Fabric: This is often a stabilizer issue, but it can be worsened by a too-heavy bobbin thread creating bulk. Double-check your stabilizer type and hooping technique, and make sure your using that lightweight 60-wt bobbin.

FAQ: Your Bobbin Thread Questions Answered

Can I use regular sewing thread in the bobbin for embroidery?
You can, but it’s not ideal. Regular all-purpose thread is usually 40 or 50 weight. It’s thicker than embroidery bobbin thread and will create more bulk on the back of your design. For best results, stick with thread made for the job.

Is bobbin thread the same as regular thread?
Not exactly. While you can sometimes use them interchangeably in a pinch, bobbin thread is engineered to be finer and smoother. It’s designed to create less lint and feed reliably at high speeds inside the bobbin case.

What is the best bobbin thread brand?
Several brands are highly regarded, including Simthread, Robison-Anton, and Madeira. Pre-wound bobbins from these companies are popular for their consistency and reliability. It’s worth testing a few to see which runs best in your specific machine.

How often should I change my bobbin?
Don’t let your bobbin run completely empty. Change it when it gets low. A very low bobbin can change the tension because the thread pull angle changes. It’s good practice to start a new project with a full or nearly full bobbin.

Do I need to adjust tension for different bobbin threads?
Maybe. If you switch from a 60-weight polyester to a 40-weight cotton, you will likely need to adjust your bobbin tension slightly. Always run a test stitch when changing thread types or weights. This prevents wasting good fabric on a tension disaster.

Remember, consistency is key in both fitness and embroidery. Using the correct what weight bobbin thread for machine embroidery—primarily 60 weight—sets a strong foundation. It keeps your machine running smooth and your stitches looking professional. Pay attention to your materials, set up with care, and you’ll avoid most common problems before they even start. Your projects will show the difference with clean, beautiful results that last.