What is Spun Polyester Thread? PET

If you’re like most people, you probably think of polyester as a fabric. But did you know that polyester can also be made into a thread?

A spun polyester thread is made from long strands of polyester that are twisted together. It’s strong and durable, making it a popular choice for sewing and embroidery. But what exactly is it made of?

The most common type of polyester is polyethylene terephthalate (PET), which is made from petroleum products.

image 1
credit: canva


  • The spinning process aligns the fibers in the same direction, which gives the thread more strength and consistency.
  • It also reduces shrinkage, resulting in a stronger and more durable seam.

The different types

It is also available in a variety of weights, from lightweight threads suitable for hand sewing to heavier threads capable of being used on sewing machines.

There are two main types: textured and untextured.

  • Textured polyester thread has a slightly rough surface that helps it grip fabric more securely. This makes it ideal for use in projects where the thread will be under a lot of stress, such as in upholstery or heavy-duty sewing projects.
  • Untextured polyester thread, on the other hand, has a smooth surface that slides more easily through the fabric. This makes it better suited for use in delicate projects or in situations where you need the thread to invisible, such as when topstitching or making buttonholes.
image 3
credit: canva

How to choose the right one for your project

The most common denier for general-purpose sewing is 60D. The higher denier threads are typically used for heavy-duty sewings such as upholstery or outdoor gear. For most general-purpose sewing, a 60D thread will be sufficient.

For lighter projects such as garments or quilting, you can use a lower denier such as 40D or 50D.

Polyester thread comes in both solid colors and variegated colors. Variegated colors are multi-colored threads that can add interest to your project.

For example, if you are sewing a brightly colored garment, you may want to use a contrasting color for added pop.


It is strong and has very little stretch, making it a good choice for sewing materials that need to resist stress, such as upholstery, leather, or vinyl.

The care and maintenance

  • Avoid using hot water or bleach, as these can damage the fibers.
  • If you are concerned about color bleeding, you can soak the thread in a solution of one part vinegar to four parts water for 30 minutes before washing.
  • Once the thread is clean, rinse it well in cool water and allow it to air dry.

Troubleshooting Problems

First, check the spool of the thread to make sure that it is not damaged or tangled. If this does not work, you may need to cut the thread and start over with a new spool.

Next, check your sewing machine to make sure that it is properly threaded. To properly thread your machine, consult your sewing machine’s manual.


These include:

  • Cotton thread is also less likely to break or tear than polyester thread.
  • Spandex thread can be useful for projects that require some give, such as elastic waistbands.

Where to buy

There are many places where you can buy it. Some common places include sewing stores, craft stores, and online retailers.

For example, lighter-weight threads are typically used for delicate fabrics such as silk, while heavier threads can be used on sturdy fabrics such as denim.


What are the benefits of using it?

The main benefits are its strength, durability, and low stretch properties. Additionally, it has good resistance to sunlight and chemicals.

Was this article helpful?