Rayon or polyester embroidery thread?

Embroidery thread for industrial machines is either manufactured in rayon or polyester. Here Peter Wright, managing director of Amaya Sales UK, explores the differences.

Most embroiderers mostly use one type and never change. When their first embroidery machine was installed it came with a set of thread. Assuming the thread runs well, they would normally use the same make for life.

This is not always the best for production or quality of finish.

Both threads have some similarities

Rayon and polyester have similar traits which sometimes make the decision of which to use more difficult.

They are both 40-weight which means that most of the stock designs that you could buy will run well without causing problems. Both would normally be stitched with a 75/11 needle, both are available in 1000 and 5000 metres, both are available in over 400 colours if you buy from the top manufacturers, both can be matched to Pantone colours for accurate colour matching. They can also be run at high speed on commercial embroidery machines although polyester would run better at the top end speeds of the machine that can run at 1,500 stitches per minute. Also both can reflect light giving a shine to the embroidery and both are Oeko-Tex certified to be free of harmful substances.

With all these similarities you will still have to consider the end product and washing types. Even with these similarities, your end product should dictate which of these 40-weight threads you choose.

Durability and performance

If your embroidery business produces work on workwear, commercial linens, uniforms or children’s clothing, polyester is the thread you should be using. Most 100% polyester threads are resistant to chlorine bleach that is used in commercial laundering. Also, products like swimwear which are in contact with chlorine in pools, will hold their colour best when embroidered with polyester thread.

A good quality rayon thread can withstand high temperatures of wash water; from 140°F for a normal household wash to 203°F for heavily soiled items, as long as detergents contain no bleaching agents, peroxide, or optical brighteners. But if there is any chance that your customer is likely to use bleach, or sell to someone who does, you will be safe by embroidering with a good quality polyester thread.

The popularity of the worn look of denim would also dictate polyester for embroidery, since polyester embroidery thread is safe for stone washing. This process – which not only breaks down the fibres with large stones, but also the colour with added bleach – results in the worn, soft and comfortable look that we associate with jeans.

Flexibility of use

When it comes to flexibility and the ability to problem solve, both rayon and polyester offer enough choices to border on confusion. Here again, both offer weights that make it possible to produce extremely small details and lettering. Finer 60-weight thread is a problem solver when it comes to including incredible detail, shading, or small readable letters in badges and logos, and it is available in both rayon and polyester. It is also a good choice when embroidering on fine, delicate fabrics.

Beyond its 60-weight for small embroidery, rayon is also available in a 30-weight, which helps improve the time and cost of producing embroidered items with lots of fill. Since it is thicker, the 30-weight requires less density, and therefore less stitches and less thread, to fill up space in a design. Commercial embroiderers who run multiple machine heads often turn to this thicker thread for some cost cutting, since it will require some 20% less thread to complete.

Rayon is also available in a very thick 12-weight for decorative stitches and embroidering on heavyweight fabrics. For incredibly small detail, there is a polyester on the market that is a 75-weight.

Also on the market is a 100% polyester matte finish polyester thread which is highly colourfast in commercial laundering and when exposed to sunlight for prolonged lengths of time. The matte finish is appealing to quilters, who like the soft look of cotton combined with the strength and durability of polyester. Also, for tone-on-tone, or where a subtle appearance is desired, a matte finish polyester is a good choice.

Ease of operation

Although you will hear embroiderers tell you that polyester is the stronger of the two threads, the run ability of both is going to come down to your machine and your knowledge of running it. Polyester’s low elongation is said to eliminate looping and puckering. The lower the elongation of the thread, the less critical the timing and the more accurate each stitch.

Rayon’s tensile strength is known worldwide, making it the choice of international designers. Considered the most flexible of embroidery threads due to its softness and pliability, rayon can be stitched out in any direction and will lie flat in the most intricate of designs. It too, will run flawlessly and without thread breaks when a good quality thread is chosen.

Rayon thread is softer to the feel on your skin although some of the higher quality polyester threads are getting closer.

Effect of thread on your machines and performance

In general, most of the high-quality rayon or polyester have no adverse effect on the workings of a machine.

A big advantage of polyester thread is its ability to withstand extremes in temperature and humidity. Rayon thread, if kept in less than ideal conditions can cause thread breaks above the normal acceptable level. If you find that you are having more thread breaks in the morning when using rayon, suspect cold, dampness or humidity.

Another thing to consider is the tensioning of different types of thread. Unless you have a machine that has automatic thread tensioning, remember that you would have to adjust your tensions when changing from different threads or polyester and rayon. If your tension of thread is not correct you will have more thread breaks and poor quality of finish.


Polyester thread is much more forgiving throughout a range of different conditions and should give you less thread breaks and more production. After saying that, rayon is preferably on fashion items because of its softness and the way it lies flat on the material.

Check Also

A world of colour and cotton

Gone are the days when you could have any colour you like as long as …

Best practices for heat presses

Andy Rogers, marketing manager at Target Transfers, outlines in this month’s transfer print column the …