Thread type depends on what you're sewing and your machine's needle size

The thread you choose matters more than most beginners realize. Using the wrong thread can jam your machine, break needles, skip stitches, or shred as you sew. The right thread runs smoothly, holds your seams together, and makes your finished project look intentional rather than accidental.

Thread comes in different weights (thicknesses), fiber contents, and finishes. Your sewing machine manual lists the thread weights it handles best—usually all-purpose thread in standard weight. But once you move beyond basic cotton garments, you'll run into situations where standard thread isn't the best choice. The key is matching the thread weight to your needle size and fabric weight, then picking a fiber that won't break or stretch when your project is worn or washed.

Key Takeaways

  • All-purpose polyester or cotton thread works for most home sewing projects and fits standard needles on any machine.
  • Thread weight (thickness) must match your needle size—thicker thread needs a larger needle, or it will shred and jam.
  • Natural fibers like cotton work best on natural fabrics like cotton and linen; polyester works on synthetics and blends.
  • Specialty threads like topstitching, metallic, and elastic exist for specific effects but require needle changes and slower machine speeds.
  • Cheap thread breaks more often and leaves lint inside your machine; mid-range brands from fabric stores perform reliably.

All-Purpose Thread for everyday sewing

All-purpose thread is what most home sewers use most of the time. It's a medium weight (usually labeled 40 or 50 weight), fits standard needles, and works on cotton, cotton blends, and light synthetics. You can find it in any fabric store in hundreds of colors. Brands like Coats & Clark, Gutermann, and Mettler are reliable mid-range choices that won't break constantly or leave excessive lint.

All-purpose thread comes in two fiber types: polyester and cotton. Polyester all-purpose is slightly more forgiving—it stretches a little, so it won't snap on knit fabrics or when seams take stress. Cotton all-purpose is traditional and works beautifully on natural fabrics, but it can break if you're sewing stretchy materials. For a beginner, polyester all-purpose in a neutral color (black, white, navy, or tan) covers 90 percent of projects.

Use all-purpose thread with a size 80/12 or 90/14 needle on most fabrics. These needle sizes are standard and come in most multipacks. If your thread keeps breaking or shredding, you likely have a needle that's dull, inserted backward, or the wrong size for your fabric weight.

Thread weight and needle size must match

Thread weight refers to thickness, measured in numbers like 30, 40, 50, or 60. Lower numbers mean thicker thread; higher numbers mean thinner thread. A 30-weight thread is noticeably thicker than a 50-weight. Your needle must have a large enough eye to accommodate the thread, or the thread will fray, shred, and jam your machine.

Here's the basic pairing: size 80/12 needles work with 40–50 weight thread (all-purpose). Size 90/14 needles also work with all-purpose but handle slightly thicker thread better. Size 100/16 needles are for heavier threads like topstitching (30 weight) or buttonhole thread. Size 70/10 needles are for fine, delicate threads on lightweight fabrics.

If you're using topstitching thread (thicker, for visible decorative stitching), you must switch to a 100/16 needle and slow your machine speed to 60 percent. Metallic thread needs a metallic needle (which has a larger eye and a special groove) and also requires slower speed. Trying to run thick thread through a small needle is the fastest way to break thread, damage your needle, and frustrate yourself.

Natural versus synthetic fiber content

Polyester thread is synthetic and works on almost everything. It's strong, doesn't rot in sunlight, and has a little give, which prevents it from snapping on knit fabrics or when seams flex. Polyester is the safest choice if you're unsure what you're sewing. It's also cheaper and widely available.

Cotton thread is natural and preferred by many sewers for cotton and linen garments because it blends visually with the fabric and has a matte finish. Cotton thread is less forgiving on stretchy fabrics—it can snap if the seam takes stress. It also rots if exposed to prolonged moisture and direct sunlight, so it's not ideal for outdoor projects or items that will be washed frequently in hot water.

Silk thread is delicate and expensive, used mainly for hand sewing or fine machine work on silk and wool. It's not practical for everyday projects. Nylon thread is stretchy and strong, used for swimwear and activewear where you need give without breakage. Most home sewers never need it.

Specialty threads for specific effects

Topstitching thread (usually 30 weight) is thicker and creates a bold, visible line of stitching. Use it when you want the thread to be part of the design—on jean seams, bag edges, or decorative lines. You must use a 100/16 needle and reduce your machine speed. Topstitching thread costs more but creates a professional, intentional look.

Metallic thread adds shine and is used for decorative work, embroidery, or holiday projects. It's fragile and prone to breaking, so use a metallic needle, slow your speed to 50–60 percent, and test on scrap fabric first. Metallic thread also requires a thread guide or tension adjustment on some machines.

Elastic thread is stretchy and used in the bobbin (the lower thread) to create gathered or smocked effects. It's not for seaming—it's purely decorative. Variegated thread changes color along its length and adds visual interest to quilting or decorative stitching. Both are specialty items; you don't need them to start sewing.

Thread quality and what cheap thread costs you

Cheap thread (often sold in multipacks at discount stores) breaks frequently, leaves lint inside your machine, and can cause tension problems. You'll spend more time rethreading and cleaning lint than you save on the thread's cost. Mid-range brands from fabric stores—Gutermann, Mettler, Coats & Clark, and Aurifil—cost a few dollars per spool and perform reliably.

Lint buildup from poor-quality thread clogs your machine's tension discs and feed dogs, eventually requiring professional cleaning. A $15 spool of good thread will sew dozens of projects without breaking. A $1 multipack will break on your second project and leave you frustrated. Buy thread from a fabric store where you can see the brand and read the label.

Store thread in a cool, dry place away from direct sunlight. Thread stored in humid basements or hot attics becomes brittle and breaks more easily. Polyester thread lasts longer in storage than cotton thread.

How to know if you have the wrong thread

If your thread keeps breaking while you sew, the problem is usually one of these: your needle is dull or inserted backward, your thread is too thick for your needle size, your tension is too tight, or your thread is old and brittle. Start by replacing your needle with a fresh one in the correct size for your fabric. Then check your machine's manual for tension settings and make sure you're threading correctly—thread should sit in every guide and tension disc.

If your thread shreds (frays into individual fibers), your needle is too small for the thread weight. Go up one needle size. If your stitches skip or look loopy, your tension may be off, but it can also mean your thread isn't seated properly in the tension discs. Rethread your machine completely, making sure the presser foot is up (this opens the tension discs) while you thread.

If you see lint accumulating around your bobbin area, you're using low-quality thread. Switch to a better brand and clean out the lint with a small brush before it causes jams.

Frequently Asked Questions

Can I use the same thread in my bobbin as on top?

Yes, for most sewing. Use all-purpose thread in both the top and bobbin. Some specialty effects (like elastic gathering) require different thread in the bobbin, but your machine manual will tell you. Bobbin thread doesn't show on the finished project, so you can use a neutral color that matches your fabric.

What thread should I use for sewing knit fabrics?

Use polyester all-purpose thread, which has a little stretch and won't snap when the fabric moves. Pair it with a ballpoint needle (size 80/12 or 90/14), which slides between fibers instead of piercing them. Cotton thread on knits will break under stress.

Do I need different thread for hand sewing versus machine sewing?

Hand-sewing thread is usually thicker and coated to prevent tangling. Machine thread is thinner and designed to flow through tension discs. You can hand-sew with machine thread, but it's harder on your fingers. Don't run hand-sewing thread through your machine—it can jam.

Why does my thread keep breaking on my new machine?

New machines often have lint or manufacturing residue inside. Run a few test seams on scrap fabric, then clean out any lint you see around the bobbin area with a small brush. Also check that you're using the correct needle size for your fabric weight and that your thread is seated in all the guides and tension discs.

Is expensive thread always better?

Not always. Mid-range brands perform as well as premium brands for most projects. Expensive thread is worth it for specialty work (metallic, topstitching on visible seams) where quality shows. For everyday sewing, a reliable mid-range brand is the better value.