Embroidery machine thread: types, weights and what to buy

For most home embroidery machines, use 40 wt polyester thread on top and a finer 60 wt polyester thread in the bobbin. Polyester is the strongest and most wash-safe of the four main types, rayon is softer and shinier but weaker, cotton gives a matte look, and metallic is best kept for small accents. Check your manual for the bobbin weight your machine wants, and store thread away from sun, heat and damp.

Start with 40 wt polyester thread on top and 60 wt polyester thread in the bobbin. That pairing suits most designs and most home embroidery machines, and it is the combination Brother sells for its own machines. The rest of this guide explains why, and when rayon, cotton, metallic or a different weight makes more sense.

Brother, Madeira and other makers are named below as examples. This site is not affiliated with any of them.

Polyester, rayon, cotton and metallic thread

The fiber decides how thread looks, how strong it is and how it behaves in the wash.

Thread	Look and feel	Strength and washing	Good for	Watch out for
Polyester	Glossy	Strong, colorfast, handles bleach	Clothing, bags, kids’ items, anything washed often	Still match needle and tension to the thread
Rayon	Soft, high sheen	Not as strong; some colors bleed or fade, dislikes bleach	Items that are rarely washed	Loops if tension is off
Cotton	Matte, natural	Fragile, can shrink	Lace and other natural-looking work	More lint in the machine
Metallic	Foil sparkle	Delicate	Small accents	Kinks and breaks easily

Polyester is the default. Madeira describes its Polyneon polyester as glossy, with colors that resist chlorine bleach, and as smooth running on high-speed machines. Dealer guides call polyester strong and resistant to fraying as it runs through the needle, say it suits items that get washed often, and one points to items such as winter coats, where its strength matters.

Rayon lays soft with a high shine. It is not as strong as polyester, and some rayon bleeds in the wash, handles bleach poorly and fades over time and in sunlight. It also needs careful tension to avoid looping.

Cotton has a flat, natural look, which is why people choose it for lace. It is fragile because it has little stretch, and it can shrink in the wash. The most common weight is 30 wt, though thicker and thinner cotton exists. Cotton sheds more lint, so clean the bobbin area more often. See our maintenance guide for how.

Metallic thread is a core wrapped in thin metal foil, which is why it kinks and breaks easily. These habits help:

Start with a fresh needle, and choose one with a larger eye. Check your needle guide and manual for sizes.
Slow the machine down, especially on detailed designs.
Use the thinnest bobbin thread you have, and check and clean the bobbin case first.
Run a sample on your real fabric. Metallic is less pliable than other threads, so you may need to loosen the tension.
Use a design digitized for metallic thread, with its density and stitch length adjusted for it.
Check thread guides for rough spots that could fray the foil.

What 40 wt and 60 wt mean

Thread weight tells you how thin the thread is, and the number runs backward: the higher the number, the finer the thread. A 60 wt thread is thinner than a 40 wt one.

40 wt is the standard. Most designs you buy are digitized for it, and it works for garments, bags and home decor.
60 wt is thinner, so it suits small lettering and fine detail.
30 wt and thicker gives a bolder look. Lower the stitch density in your software and use a bigger needle, such as 90/14.

Match the needle to the thread when you change the weight. Guides differ a little here. Madeira lists size 65/9 or 75/11 for its Polyneon polyester, while one dealer pairs 40 wt with 80/12 and 90/14 with heavier fabric or thicker thread. Use your needle guide and a scrap of the real fabric. Check your manual too, since it may limit which top thread weights your machine accepts. Our thread weight glossary entry has a short definition.

Bobbin thread

Embroidery bobbin thread is finer than the top thread. A thick bobbin thread adds bulk to the back of dense designs and can cause thread breaks and tension problems. One embroidery site says recommended bobbin weights are almost always 60 wt or higher, and Brother’s own bobbin thread is 60 wt. Some machines use 90 wt, so check your manual before you buy a big supply.

On the back of your stitching, the bobbin thread should stay in the center, and one dealer says top thread should show across about two-thirds of the back. If the bobbin thread is showing on top of your embroidery instead, see our bobbin thread troubleshooting guide.

Pre-wound or self-wound? One dealer says pre-wound bobbins are wound evenly and hold more thread. Another embroidery site likes them but warns of occasional problems, such as a machine that does not notice when the thread runs low or a bobbin wound too full to fit. Winding your own lets you choose any color or fiber, but wind smoothly and check the bobbin for cracks or rough edges first. Brother’s pre-wound bobbins are a good example: a 10-pack of size 11.5 clear bobbins, each holding 105 yd (about 96 m) of 60 wt white polyester. Brother’s list of compatible machines includes the PE800, PE900, SE1900 and SE2000. Always use the bobbin style your own machine requires.

You rarely need to match bobbin color to the top thread, since it should not show on the front. It is worth matching when the back of the work will be seen, as on free-standing lace or in-the-hoop projects.

Cones, spools and thread stands

Both hold the same kind of thread. The difference is how much.

Spools are the small snap spools that come in color sets. Brother’s 63-color set uses 1,100 yd (about 1,000 m) double-snap spools, which stop the thread unwinding.
Cones hold much more. Madeira sells its 40 wt Polyneon on 1,100 yd spools and on 5,500 yd (about 5,000 m) cones, five times as much. A cone makes sense for white, black or any color you use constantly.

Cones and other oversized spools may not fit your machine’s built-in spool pin, so you may need a separate thread stand. A stand also helps with metallic thread. One embroidery guide advises stacked thread on a vertical pin and cross-wound thread on a horizontal holder, so follow your manual. To work out how much thread a job needs, use our thread calculator.

Brother embroidery thread and other brands

Brother’s Pacesetter set is 100% polyester, 40 wt, on 1,100 yd (about 1,000 m) spools, and Brother says it is designed for its own embroidery machines. That makes it an easy first choice for a Brother owner, but it is not the only choice. Madeira Polyneon is a 100% polyester thread sold in 40, 60 and 75 wt, and Madeira describes it as durable and smooth running on high-speed machines. Isacord, Floriani, Sulky and Robison-Anton are other makers with their own color ranges, as the next section explains.

Pick one line for each project where you can. Shades and sheen differ between brands, and mixing them within one design is where mismatches show.

Thread charts and matching colors across brands

Every maker numbers its colors differently, so a Madeira number is not an Isacord number. Conversion charts list the nearest shade in another brand. One embroidery site’s chart page covers about 20 brands, including Brother, Floriani, Isacord, Madeira, Robison-Anton and Sulky. A few points keep you out of trouble:

A chart gives the closest available shade, which is not always a good match, and manufacturers change numbers over time.
Metallic and variegated threads are the hardest to convert.
Some brands number their colors to follow Brother’s chart, and many newer machines have thread charts built in, so check your manual.
A DST file has no thread colors, so the machine or software assigns them. Many other formats include a color list, but treat it as a starting point.
Spot-check every match. Screen colors are only approximate, so hold the real spool against your fabric in daylight, or stitch a small sample.

Storing thread

Heat, light and damp wear thread out before you use it.

Keep it out of direct sunlight, which fades color and can make thread brittle.
Aim for about 50% humidity and 65-75°F (18-24°C). Avoid attics and basements. A dehumidifier or silica gel packs in the box can help.
Use a clean, closed drawer or box so dust stays off the thread.
Use snap closures, netting or ties to keep spools from unwinding.

Before a big job, pull a short length between your hands. One guide says thread that breaks without much effort should be thrown out. If your thread keeps snapping, work through our thread breaking checklist before blaming the thread alone.

What to buy first

40 wt polyester top thread. A small set of basic colors plus white and black is enough to start. Add colors as your designs need them.
60 wt polyester bobbin thread in white and black, or pre-wound bobbins that match your machine’s bobbin style.
Embroidery needles in the sizes your manual lists for your thread and fabric.
A thread stand, only if you buy cones.
Metallic, 30 wt and rayon, when a specific project calls for them.

Frequently asked questions

What thread does a Brother embroidery machine use?

Brother sells 40 wt, 100% polyester embroidery thread on 1,100 yd (about 1,000 m) spools and says it is designed for its embroidery machines. Many embroiderers also use other 40 wt brands such as Madeira, so follow any weight limits in your manual.

What bobbin thread should I use in a Brother embroidery machine?

Brother sells 60 wt white polyester bobbin thread in pre-wound size 11.5 bobbins, 105 yd (about 96 m) each. Its list of compatible models includes the PE800, PE900, SE1900 and SE2000. Check your manual for the bobbin style your machine takes.

Is polyester or rayon better for machine embroidery?

Polyester is the safer default because it is strong, colorfast and handles washing and bleach. Rayon gives a softer feel and higher sheen but is not as strong, and some rayon bleeds or fades, so it suits items that are rarely washed.

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

You can, but a top-weight thread in the bobbin adds bulk to the back and can cause thread breaks and tension problems, so most embroiderers use a finer bobbin thread. Matching top and bobbin thread is worth it when the back will be seen, such as on free-standing lace.

How should I store embroidery thread?

Keep it in a clean, closed container away from direct sun, in a room that stays around 65-75°F (18-24°C) and about 50% humidity. Avoid attics and basements, where temperatures swing.