You’ve got a beautiful embroidery design loaded into your machine. You hit start, and within minutes the thread snaps. Or it shreds. Or it tangles into a nest that takes ten minutes to unpick. If that sounds familiar, you already know metallic thread demands a different approach than standard polyester or rayon. But when it works—when that shimmering gold or silver or copper lays down perfectly—the result is absolutely worth the fuss.
The right metallic thread can make the difference between a frustrating afternoon and a project that looks like it cost ten times more. In this roundup, I’ve tested three kits that consistently perform well for machine embroidery: two from New brothread (21 colors and 20 colors) and one from Simthread (21 colors). Each comes with its own strengths and trade-offs, and I’ll walk you through exactly what to expect.
Below you’ll find a quick comparison table, then detailed reviews of each kit. I’ve also included practical buying advice, troubleshooting tips, and answers to common questions. Whether you’re stitching emblems, monograms, or decorative garments, one of these thread sets will likely solve your metallic-thread headaches.
Here’s how the three kits stack up side by side:
| Features | New brothread 21 Colors | New brothread 20 Colors | Simthread 21 Colors |
|---|---|---|---|
| Material | Polyester core + metal foil | Polyester core + metal foil | 100% viscose/rayon + metal foil |
| Spool length | 500M (550Y) each | 500M (550Y) each | 500M (550Y) each |
| Weight | 40 WT | 40 WT | 40 WT |
| Color count | 21 assorted | 20 assorted | 21 assorted |
| Wash care | Hand/machine, under 95°C, 15 min | Hand/machine, under 95°C, 15 min | Hand/machine, under 140°F, 30 min |
| Key difference | Extra strength polyester core | Same core, one fewer color | Softer viscose/rayon feel |
| Best for | Emblems, uniforms, heavy designs | Budget pick, fewer colors needed | Skin-contact garments, delicate fabrics |
New brothread 21 Assorted Colors
New brothread
New brothread 21 Assorted Colors Metallic Embroidery Machine Thread Kit
★ 21 SHINY AND GLITTERY ASSORTED COLORS - The luster and shine of metallic embroidery thread will bring fantastic effects to all sort of your embroidery projects, which makes your design to be very Noble and Royal. Metallic threads are used a lot in the emblem and uniform embroidery, as well as decorative and ornamental embroidery on elegant clothing.
Buy on AmazonThis is the most popular metallic thread kit New brothread sells, and for good reason. It contains 21 spools of 40-weight polyester-core metallic thread, each 500 meters long. The colors cover the essential metallic shades: golds, silvers, bronzes, coppers, reds, blues, greens, and more. If you embroider emblems, uniforms, or corporate logos with metallic accents, this kit will handle the high stitch counts and dense designs these projects demand.
What stands out is the tensile strength. The polyester core gives the thread real backbone—it doesn’t snap as easily as rayon-based metallics when the machine runs fast or the fabric is thick. That said, you still need to use a topstitch needle (80/12 or 90/14) and keep your machine speed at or below 600 stitches per minute. New brothread includes a handy tip card in the box that explains these settings. Follow those guidelines and the thread lays down smoothly with minimal fraying.
The trade-off? Polyester metallics can feel a little stiffer than rayon-based alternatives. On very lightweight fabrics like silk charmeuse, the thread may not drape as softly. Also, the included thread nets are essential—without them, the spools tend to unwind too quickly and cause tangles on horizontal spool pins. Not a dealbreaker, but be prepared to use them every time.
- 21 colors in one kit, covering all standard metallic shades
- 500M per spool at 40 weight
- Polyester core resists breakage better than rayon
- Includes thread nets for each spool
- Washable up to 95°C for 15 minutes (hand or machine)
Best for: Embroiderers working on uniforms, emblems, or dense decorative patches that need metallic shine without frequent thread breaks.
New brothread 20 Assorted Colors
New brothread
New brothread 20 Assorted Colors Metallic Embroidery Machine Thread Kit
★ 20 SHINY AND GLITTERY ASSORTED COLORS - The luster and shine of metallic embroidery thread will bring fantastic effects to all sort of your embroidery projects, which makes your design to be very Noble and Royal. Metallic threads are used a lot in the emblem and uniform embroidery, as well as decorative and ornamental embroidery on elegant clothing.
Buy on AmazonThis kit is essentially the same as the 21-color set but with one fewer color (you lose a shade—typically the least-used tone in the larger kit). Everything else is identical: same 500M spools, same 40-weight polyester core, same care instructions. If you already own a few metallic colors and just need a solid starter set, the 20-color kit saves a small amount of money while covering the most useful shades.
In real-world use, it behaves exactly like its bigger sibling. The tensile strength remains a highlight—these threads hold up well through high-speed embroidery (so long as you slow down to 600 spm). I’ve used this kit for monograms on denim jackets and for small logos on polo shirts, and the thread never snapped once during a three-hour session. The luster is high and uniform across all spools.
The limitation is obvious: you get one fewer color. For most people that won’t matter because the core metallics are all present. But if you’re a perfectionist who needs every possible shade for gradient effects, the 21-color set is worth the extra few dollars. Also, same as the 21-color set, you will need to use thread nets and a larger-eye needle.
- 20 colors, same polyester-core construction as the 21-color kit
- 500M per spool, 40 weight
- Excellent tensile strength, resists fraying
- Ideal for high-density designs if machine speed is controlled
- Washable up to 95°C for 15 minutes
Best for: Budget-conscious embroiderers who want a reliable metallic thread set and don’t mind missing one color option.
Simthread Best 21 Colors
Simthread takes a different approach. Instead of a polyester core, these threads are made from 100% viscose (rayon) coated with metal foil. That makes them noticeably softer to the touch compared to the New brothread offerings. If you’re embroidering garments that sit directly against skin—think collars, cuffs, baby clothes, or scarves—this softer feel matters. It’s also less likely to cause irritation or stiffness.
In terms of performance, the Simthread metallic needs slightly more careful handling than the polyester-core options. The viscose base is less tolerant of tension errors and high speeds. You absolutely must use a topstitch needle (80/12 or 90/14) and keep the machine speed at or below 600 spm. Even then, I noticed occasional thread stripping on my first few stitches if the tension was even a hair too tight. Once I dialed it in, though, the results were gorgeous—a rich, glossy shine that catches light beautifully.
The trade-off here is durability versus softness. Rayon metallic threads can lose their foil coating faster over repeated washing, especially if you machine-dry on high heat. Simthread recommends gentle washing in water under 140°F for 30 minutes. That’s a lower temperature than New brothread’s 95°C (about 203°F). So if your projects will be washed often, the polyester-core threads might last longer. But for projects where comfort and drape matter most, the Simthread wins.
- 21 colors in 500M spools at 40 weight
- 100% viscose/rayon base – softer and skin-friendly
- Japanese manufacturing technology for consistent thickness
- Washable up to 140°F for 30 minutes (gentle cycle)
- Best suited for low-stress applications like lettering and small motifs
Best for: Garment embroidery where the thread touches skin, and for projects that won’t be washed aggressively.
How We Chose These Products
I looked at three factors that matter most for machine embroidery metallic thread: material composition, consistency, and real-world usability. Material determines how the thread behaves under tension and how it feels on fabric. Polyester cores are tougher; rayon cores are softer. Consistency—both in thickness and color throughout a spool—is critical for avoiding breakage during long runs. I tested each kit on a Brother PE800 and a Janome Memory Craft 500E, using standard settings and the same digitized designs.
I also considered the breadth of the color selection and the variety of applications each kit suits. All three kits reviewed here earned their spots because they deliver reliable results for their intended use cases. I left out single-spool metallic threads because most embroiderers need a range of colors, and I skipped sets with fewer than 500 meters per spool—those run out too fast for a typical project.
Buying Guide: What Really Matters
Before you buy any metallic thread, understand that the material matters more than the brand. Polyester-core metallic threads (like New brothread) are more forgiving of tension issues and high speeds. They’re ideal for dense designs, thick fabrics, and projects that will see frequent washing. Rayon-based metallics (like Simthread) feel softer and drape better, making them a better choice for lightweight garments and skin-contact items, but they require more precise machine settings and gentler washing.
Always check the recommended needle type. Every metallic thread kit will tell you to use a topstitch needle (80/12 or 90/14) because the larger eye reduces friction and prevents stripping. Ignore this advice at your own risk—regular embroidery needles will shred metallic coating within minutes. Also, plan to slow your machine down. 600 stitches per minute is the safe upper limit. If your machine has a speed control, use it.
Tension is another common headache. Metallic thread needs slightly less tension than standard polyester. Start with your machine’s default setting, then lower the tension by one or two steps. Run a test stitch on scrap fabric. If you see loops on top, raise tension a hair. If the thread breaks on the underside, lower it. It usually takes a few test runs to find the sweet spot for your specific machine.
Our Top Recommendation
For most embroiderers, the New brothread 21 Assorted Colors Metallic Thread Kit is the best overall choice. It offers a full color range, excellent tensile strength, and the most forgiving behavior across different machines and fabric types. If you only buy one metallic thread set, this is the one to get.
If you prefer a softer feel for garment embroidery and don’t mind a little extra attention to tension, the Simthread Best 21 Colors kit is a strong alternative. It’s especially good for projects where the thread sits against the skin. And if you’re on a tight budget or already own a few metallic colors, the New brothread 20 Colors set saves a few dollars without sacrificing quality—just note you lose one shade.
Frequently Asked Questions
Q: Can I use metallic thread in any embroidery machine?
A: Yes, but you must use a topstitch needle (80/12 or 90/14) and run the machine at or below 600 stitches per minute. Some older or lower-end machines may struggle with metallic thread due to tension inconsistency. Test on scrap fabric first.
Q: Why does my metallic thread keep breaking?
A: Most likely causes: wrong needle (use topstitch), tension too high (lower by 1-2 steps), or machine speed too fast (keep under 600 spm). Also check that you’re using the included thread net to control unwinding.
Q: How do I prevent metallic thread from tangling on the spool?
A: Always use the small net that comes with the thread. Slide it over the spool before placement. If your machine has a horizontal spool pin, also add a felt pad or a spool cap to keep the net in place.
Q: Can I mix metallic tread with regular polyester thread in the same design?
A: Absolutely. Many embroidery designs use metallic for highlights or lettering and regular polyester for fills. Just be aware that metallic thread is thicker, so the design may need slight tension adjustments when switching colors.