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Filament Sewing Thread vs Spun Thread

Filament sewing thread is made up of continuous filaments of synthetic fibers such as polyester, nylon or rayon. This thread is smooth and strong, it is great for use in machine sewing as it will not break easily during use. The continuous filaments make this thread very strong and resistant to breakage, making it ideal for heavy-duty applications. Due to its smoothness, it can also reduce the chances of tangling or knotting while sewing.

Staple thread sewing thread is made up of short fibers, typically cotton or polyester. These threads are intertwined to create a strand and are then twisted together. This type of thread is more suitable for hand sewing as it has more texture and grip, which makes it easier to knot and maneuver. Spun thread tends to be less strong than filament thread, but it can be easier to work with for some applications.

The key differences between the two types of thread are the materials used and the method of manufacturing. Filament thread is smoother and stronger, while staple thread is more textured and easier to handle for hand sewing.

Filament Sewing Thread and Staple Spun Polyester Thread

automotive sewing thread
automotive sewing thread

Filament sewing thread and staple spun thread are two different types of thread with distinct characteristics.

Filament Sewing Thread

Filament sewing thread is crafted from continuous fibers, typically synthetic materials such as polyester or nylon. These fibers are meticulously extruded, forming a single continuous strand. This manufacturing process results in a thread that boasts remarkable strength and consistency. The absence of breaks or interruptions in the fibers contributes to the exceptional tensile strength that filament threads are known for. This makes them particularly suitable for applications where durability is a priority.

  • Filament sewing thread is made from continuous filaments of synthetic fibers like polyester, nylon, or rayon.
  • It is strong and smooth, making it great for machine sewing and heavy-duty applications.
  • It is less prone to breakage and tangling, providing consistent tension throughout the sewing process.

Staple Spun Polyester Thread

In contrast, spun thread is made from shorter staple fibers, often including natural fibers like cotton or blends of different materials. The manufacturing process for spun thread involves twisting these shorter fibers together to create a thread with a slightly textured appearance. This texture gives spun threads a softer and more pliable feel compared to filament threads. While spun threads may not have the same tensile strength as filament threads, they offer their unique advantages, especially when used for specific projects.

  • Spun polyester thread is made by spinning together short polyester fibers, which have been cut from longer polyester fibers.
  • It has a fuzzy texture and offers excellent seam elasticity, which makes it ideal for knit and stretchy fabrics.
  • It is available in many colors and is an affordable option for most sewing projects.
  • It can break more easily than filament thread and may require frequent adjustments to the sewing machine tension.

Filament Sewing Thread vs Spun Thread

  • Strength: Filament thread tends to be stronger than spun thread due to the continuous filaments, making it better for heavy-duty applications.
  • Texture: Spun thread has a slightly fuzzy texture that can help it grip fabric more easily, making it better for hand sewing.
  • Appearance: Filament thread is smoother and has a shinier appearance, while spun thread has a slightly matte appearance.
  • Price: Filament thread is usually more expensive than spun thread due to the manufacturing process.
  • Ultimately, the choice between filament sewing thread and spun thread will depend on the specific project and method of stitching being used. Filament thread is better for heavy-duty applications, while spun thread is better for hand sewing and projects that require a more textured look.

Strength and Durability

  • Filament Sewing Thread: Filament threads shine in terms of strength and durability. The continuous, unbroken fibers that make up these threads result in high tensile strength, making them an excellent choice for heavy-duty applications. Whether you’re working with heavyweight fabrics, leather, or upholstery, filament sewing threads can handle the stress and strain of demanding sewing tasks. The robust nature of these threads ensures that your seams remain intact, providing long-lasting results.
  • Spun Thread: While spun threads may not match the tensile strength of filament threads, they offer their own brand of versatility. Spun threads, especially those made from natural fibers like cotton, are well-suited for softer and more delicate fabrics. They provide a gentler touch, making them a popular choice for apparel, quilting, and projects where a softer finish is desired. Their pliability allows them to gracefully adapt to the contours of fabrics, creating seamless and comfortable stitches.

Filament sewing thread is stronger and smoother than spun polyester thread, making it suitable for machine sewing applications where strength, durability and even coverage is needed, while spun polyester thread is an excellent choice for sewing projects involving elastic fabrics or where stretchable seams are needed or when working on lighter fabrics. The choice between these two types of thread depends on the specifics of the sewing project and the materials being used.


Filament sewing thread and spun thread can be used in a variety of sewing applications, although the specific uses will depend on the properties of the thread and the requirements of the project.

Filament Sewing Thread Applications

  • Heavy-duty sewing: Filament sewing thread is well-suited for durable, heavy-duty sewing projects like upholstery, outdoor gear such as tents, sewing leathers, tarps, sails…
  • Machine sewing: It’s strong and smooth properties make filament thread ideal for use in machine sewing applications that require even stitches.
  • Embroidery: It’s strong characteristic makes it suitable for embroidery work, and its smoothness helps it glide easily through the fabric being embroidered.

Spun Thread Applications

  • Knit fabrics: Spun thread is best used for knitting and stretchy fabrics since it has some added elasticity and gives garments some flexibility.
  • Lighter fabrics: Spun thread tends to be thinner than filament thread making it a better option for lightweight fabric sewing projects such as t-shirts, blouses and other lightweight textiles.
  • Hand Sewing: Spun thread is also a good choice for hand sewing as its fuzzy texture allows it to grip the fabric better, making the needle much easier to pass through the fabrics being sewed on.

Applications and Best Uses

Now, let’s delve into the specific applications where each type of thread shines:

Type of ThreadApplications
Filament Thread– Heavy-duty sewing (e.g., upholstery, leather)
– Industrial sewing
– Projects requiring exceptional strength and durability
– Fabrics that can withstand tension and stress
– High-speed sewing machines
Spun Thread– Apparel and clothing construction
– Quilting
– Soft and lightweight fabrics
– Projects where a softer finish is desired
– Versatile for a wide range of sewing projects

Choosing the Right Thread

When deciding between filament sewing thread and spun thread, consider the specific requirements of your sewing project. If you’re working with heavy fabrics, need superior strength, or are using high-speed sewing machines, filament thread may be the optimal choice. On the other hand, if you’re sewing delicate materials, creating apparel, or aiming for a softer finish, spun thread could be the perfect fit. Remember that both types of threads have their unique advantages, and selecting the appropriate one will enhance the quality and longevity of your sewing creations.


Both filament sewing thread and spun thread may be used for a variety of applications in different sewing projects. However, filament thread is typically stronger and smoother, making it ideal for heavy-duty and machine sewing projects, while spun thread offers more give and versatility which makes it a better choice when working with lighter fabrics and garments that will need flexibility and stretch.