Choosing the best thread for machine embroidery makes a real difference to the finished result. The good news is that there is no single correct answer. The best thread depends on your project, your fabric, and the look you want to achieve.
In most cases, polyester embroidery thread is the best all-around choice for machine embroidery due to its strength, colourfastness, and reliability. Rayon offers a softer sheen for decorative work, while cotton is ideal for quilting and natural fibre projects.
One thing applies across all thread types. Quality matters. A high-quality thread gives consistent tension, fewer thread breaks, and a more reliable stitch, whether you are stitching a single design or running multiple repeats.
A Note on Our Approach at Quilt Direct
At Quilt Direct, quality always comes first. We carefully select the threads we stock for performance, consistency, and reliability. Our preferred choices are also strong from an environmental perspective.
In our studio, we are moving towards natural and recycled fibre threads for all new projects and samples, with Aurifil and Isacord recycled polyester as our threads of choice. At the same time, we continue to use our existing rayon and polyester stocks rather than discarding them, as using what you already have remains the most sensible and sustainable approach.
What Thread Weight Should You Use?
Most machine embroidery designs are created to run with 40wt thread, which is considered the standard for embroidery machines. Using 40wt thread gives the best balance between coverage and detail, allowing designs to stitch out cleanly without appearing too heavy or too fine.
In most cases, 40wt is the correct choice for standard machine embroidery designs. Unless a design specifically states otherwise, 40wt thread will usually give the most reliable and consistent results.
Why 40wt Is the Standard for Machine Embroidery
Machine embroidery designs are digitised specifically for 40wt thread. The stitch count, density, and spacing are all calculated with 40wt in mind, which is why it gives the most reliable results straight out of the box.
Using a heavier thread, or reducing the size of a design, has the same effect: the stitches become compressed and the thread begins to overlap, losing detail and causing the design to look dense or distorted. The reverse is also true: a finer thread or an enlarged design can leave gaps in coverage, making the stitching appear thin or uneven.
Resizing Designs
Most embroidery designs can be resized, but there are limits. As a general rule, the maximum safe resize range is plus or minus 20% of the original size. Beyond this, the stitch density becomes too compressed or too sparse to stitch out cleanly.
In practice, we recommend keeping resizing to no more than 10% in either direction for the best results. If you need a significantly different size, it is always better to source a design digitised at the size you need, or have it professionally re-digitised.
Finer Thread Weights: 60wt and 80wt
While 40wt is the standard for most machine embroidery, finer weights have their place for specialist projects. Because these designs need to be digitised specifically for finer thread, you cannot simply swap a 40wt thread for a 60wt or 80wt in a standard design: the stitch density will be too high and the result will be compressed and heavy.
When a design has been created for finer thread, the results can be beautiful:
- 60wt works well for small, detailed motifs and fine lettering where a lighter touch is needed
- 80wt is ideal for very delicate work such as lettering on handkerchiefs, shadow work embroidery, and sheer fabrics like voile, where a heavier thread would overwhelm the fabric
The finer the thread, the more delicate the finish, and the more important it is that your design has been digitised to match.
What Thread Is Best for Machine Embroidery?
As a simple guide:
- Polyester is the best all-around thread for most machine embroidery
- Rayon is best for decorative work where sheen matters
- Cotton is ideal for quilting and natural or more muted finishes
Polyester is stronger and more colourfast than rayon, while rayon offers a softer, more traditional sheen. Cotton provides a matte finish that works beautifully on quilts and fine fabrics.
Polyester Embroidery Thread
Trilobal polyester is now the standard for machine embroidery. It is strong, colourfast, and performs consistently even at high machine speeds. It is particularly well-suited to items that need regular washing.
If you are embroidering everyday items such as bags, clothing, or children's wear, polyester is usually the most practical choice.
Using a high-quality polyester thread helps reduce thread breaks and keeps your stitching running smoothly throughout a design.
Amann Isacord: A Professional Standard
Amann Isacord is widely regarded as one of the finest polyester embroidery threads available and is used by professional embroiderers worldwide.
Available in over 400 colours, Isacord 40wt combines durability with excellent sheen and consistency. It runs smoothly through both domestic and commercial machines, with minimal interruption.
- 40wt, 1000m spools: the standard for machine embroidery, suitable for the vast majority of designs and fabrics
- Colourfast and washable: ideal for garments, workwear, and anything that needs regular laundering
- Consistent tension: winds evenly and runs reliably, reducing the need for constant re-threading or tension adjustments
- Over 400 colours: one of the widest colour ranges available, with an Isacord shade card available to help you choose
- OEKO-TEX certified: tested for harmful substances and safe for use on clothing and items in contact with skin
- 100% recycled polyester option: Amann also produces Isacord from 100% recycled polyester, offering the same performance with a reduced environmental footprint
Browse the full Amann Isacord 40wt 1000m range at Quilt Direct.
Mettler Polysheen: The Same Quality in Smaller Amounts
Mettler Polysheen is the same high-quality 40wt trilobal polyester thread as Isacord, produced to the same professional standard but available in smaller spool sizes. This makes it an ideal choice for smaller projects, multi-colour designs where you need a range of colours without committing to large quantities, or simply for trying out new shades before investing in larger spools.
- 40wt polyester: the same thread construction and performance as Isacord
- Smaller spool sizes: more manageable for home embroiderers and multi-colour projects
- Wide colour range: available in a broad palette, with a Mettler Polysheen shade card to help you plan your colour choices
Browse the Mettler Polysheen small spools range at Quilt Direct.
Rayon (Viscose) Embroidery Thread
Rayon, sometimes labelled viscose, is made from cellulose derived from wood pulp and has long been valued for its beautiful sheen.
It produces a soft, silky finish that polyester does not fully replicate. Rayon is best used for decorative embroidery where appearance is the priority rather than durability.
It works particularly well for:
- heirloom projects
- decorative pieces
- fine or delicate fabrics
Worth noting: We currently have a clearance selection of rayon threads at reduced prices, a good opportunity to try this thread type or stock up on favourite colours while stocks last.
Cotton Embroidery Thread: Aurifil
Aurifil is one of the most respected names in cotton thread, and a firm favourite in the Quilt Direct studio. Made from long-staple (Mako) Egyptian cotton, Aurifil produces less lint than many other cotton threads, which means cleaner running through your machine and less residue build-up over time. Two weights work particularly well for machine embroidery or digital quilting.
- Aurifil 40wt: ideal for open, airy designs where you want the thread to show without being heavy
- Aurifil 50wt: better suited to denser designs, giving a finer, more refined finish
Aurifil is also an environmentally considered choice on several fronts. It carries OEKO-TEX certification, meaning it has been tested for harmful substances and is safe for use on clothing and on items that come into contact with skin. The spool centres are made from recyclable plastic, further reducing waste.
Metallic and Pearlescence Thread
Metallic and pearlescence threads add sparkle, shimmer, and a luxurious finish to embroidery projects, from festive designs and decorative monograms to special occasion gifts and statement pieces.
These threads require a little more care than standard polyester or rayon. Running your machine at a slower speed, using a larger needle (a 90/14 metallic needle is recommended), and ensuring your tension is correctly set will all help achieve a smooth, consistent result. Metallic threads can be more prone to shredding or breaking if the machine is run too fast or the needle is too small. They also work best in designs with lower stitch density, giving the thread room to catch the light.
Kingstar Metallic Thread is a true metallic thread, available at Quilt Direct in two weights:
- Kingstar 40wt 1000m: the standard weight for most metallic embroidery designs, giving good coverage and a bold, reflective finish
- Kingstar 70wt 1000m: a finer metallic for more delicate designs where you want shimmer without the weight of a standard metallic
Amann Yenmet is a pearlescence thread rather than a true metallic. Where Kingstar gives a bold, reflective sparkle, Yenmet produces a softer, iridescent sheen, beautiful for projects where you want a subtle lustre rather than full metallic impact. Available in 40wt 500m spools in a range of colours.
At Quilt Direct we stock a carefully selected range of quality metallic and pearlescence threads:
- Kingstar Metallic 40wt 1000m: bold, reflective metallic at the standard embroidery weight
- Kingstar Metallic 70wt 1000m: finer metallic for delicate designs and subtle shimmer
- Amann Yenmet 40wt: pearlescence thread for a soft, iridescent sheen rather than full metallic sparkle
- Mettler Metallic: high-quality metallic from a trusted thread brand, available in small and large spools
Browse the full Metallic Threads range at Quilt Direct.
Best Thread for Different Uses
Choosing the right thread becomes much easier when you match it to the job:
- Everyday items, workwear, children's clothing
Polyester, such as Isacord, for durability and colourfastness - Professional or high-volume embroidery
Amann Isacord for consistency and reliable performance - Smaller projects or multi-colour designs
Mettler Polysheen for the same quality thread in more manageable spool sizes - Environmentally conscious projects
Aurifil cotton or Isacord recycled polyester - Decorative or heirloom pieces
Rayon for softness and sheen - Quilts with the embroidery module
Aurifil 28wt, 40wt or 50wt for a natural, matte finish - Fine cotton fabrics
Aurifil 50wt or 80wt for a natural, matte finish - Festive, decorative, or special occasion projects
Kingstar, Yenmet, or Mettler Metallic for sparkle and shimmer - Very fine detail, handkerchiefs, voile, shadow work
60wt or 80wt thread digitised for finer weights
Whichever thread you choose, quality matters. A good thread runs consistently, holds its colour, and lets your machine do its job without interruption. Ultimately, the final choice is always yours, and experimenting with different threads on a test piece before committing to your project is always worthwhile.
Don't Forget Your Needle
The right thread deserves the right needle. Using a needle suited to your thread type and fabric makes a real difference to stitch quality and helps protect both your thread and your machine. As a general rule, a 75/11 or 80/12 embroidery E or Jersey SUK needle is the correct starting point for most 40wt embroidery threads on standard cotton fabrics. For metallic and pearlescence threads, a 90/14 metallic needle is recommended.
For full guidance on needle types, sizes, and when to change them, see our Sewing Machine Needles guide.
Shop Embroidery Threads at Quilt Direct
Browse our full range of Amann Isacord threads, Mettler Polysheen, Aurifil, rayon threads, and metallic threads at Quilt Direct. If you're not sure which thread is right for your project, feel free to get in touch. We're always happy to help.
