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Filament Sewing Thread: Basics, Top 3 Pros, Cons, and Types

Filament sewing thread is a type of sewing thread made from synthetic fibers. The synthetic fibers used in this type of thread are typically polyester, nylon or rayon, which are extruded into long continuous filaments. These filaments are then twisted together to form a single strand of thread.

Top 3 Pros and Cons of Filament Sewing Thread


  • Strength: Filament sewing thread is generally stronger than staple threads due to the continuous filaments that make up the thread. This makes it a good choice for sewing heavy-duty fabrics or items that will be exposed to a lot of wear and tear.
  • Smoothness: Filament thread is very smooth, which can make it glide more easily through fabric and reduce the risk of tangling or knotting.
  • Cleanliness: Because filament thread is made from synthetic fibers, it is less likely to attract dust or lint than natural fiber thread.


  • Fraying: Filament thread can fray more easily than other types of thread, which can make it difficult to work with.
  • Not absorbent: Synthetic fibers do not absorb moisture well, which can make filament thread a poor choice for sewing items such as towels or other absorbent materials.
  • Limited color selection: Because filament thread is synthetic, it can be difficult to dye, which can limit the color selection available.

Top 3 types of filament sewing thread

  • Polyester filament thread: This is the most common type of filament sewing thread. It is strong and durable, and is resistant to UV rays, moisture and chemicals.
  • Nylon filament thread: Nylon filament thread is similar to polyester filament thread in terms of strength and durability, but it tends to be more elastic and stretchy.
  • Rayon filament thread: Rayon filament thread is less common than polyester or nylon, but it is known for its softness and sheen. It is often used in embroidery projects.

Applications of Filament Sewing Thread

filament sewing thread
Polyester filament sewing thread

Filament sewing thread has a wide range of applications due to its strength and durability. Some common uses include:

  • Sewing heavy-duty fabrics such as denim, canvas or leather
  • Upholstery
  • Drapery making
  • Quilting
  • Embroidery
  • Industrial sewing applications such as automotive manufacturing or marine applications

When choosing a filament sewing thread, it’s important to consider the thickness of the thread relative to the weight of the fabric, as well as the color fastness and UV resistance of the thread if the project will be exposed to sunlight. Additionally, the type of filament (polyester, nylon or rayon) may have different properties, so it’s important to choose the right type of thread for the specific project.

Heavy Duty Filament Sewing Thread

Tex 60, Tex 90, Tex 135, and Tex 270 are heavy-duty sizes of filament sewing thread. Here’s a breakdown of each size:

  • Tex 60: This is a very heavy thread that is suitable for rugged applications, such as sewing leather, canvas or vinyl. It is also used in upholstery and other heavy fabrics.
  • Tex 90: This is an even heavier thread than Tex 60 and is often used in industrial applications, such as automotive or marine canvas applications.
  • Tex 135: This is an extremely heavy thread that is suitable for the biggest, most rugged sewing projects. It is commonly used in military and industrial applications for webbing, gear, and heavy-duty sewing projects.
  • Tex 270: This is an extra heavy-duty thread mainly used for leatherwork or other tough sewing projects that need a very strong thread.

These heavy-duty filament sewing threads are commonly used for sewing heavy-duty applications that require additional strength, durability and a bigger thread. The thickness of these threads provides long-lasting hold and is perfect for use in items such as bags, tarps, tents, sails, canvas fabrics and other thick materials where stronger threads are needed. It is important to choose the right size of thread for the material being sewn in order to ensure the strength and quality of the final product.