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Leather Thread – Learn Materials, Thickness, and Best Uses

A large part of working with leather is sewing, also called stitching. With leather craft being a hobby of endless creativity, the thread for it is no different. Since starting my leather craft journey, I have tried various threads and still explore with every chance I get. 

Leather thread is a fiber strand used to add design or sew two pieces of leather together. Leather thread is commonly made from polyester, nylon, or linen in various colors of bonded, flat, or round shapes. Depending on the type and spool size, the leather thread costs $5–$100.

To help navigate the differences in leather threads, this article will cover the characteristics of each, so you can decide which leather thread is best for you. 

What Is a Leather Thread?

Leather thread is a fiber strand made from polyester, nylon, or linen and used for sewing two pieces of leather together. Many variations of leather thread exist, including different colors, sizes, shapes, and coatings.

Each variation will provide a unique look to the finished product, but some may also affect durability. Which one you use is a personal preference, as all kinds of leather threads have benefits and downsides. 

What We’ll Explore

  • Clearing up Myths & Misconceptions
  • When You Might Use Leather Thread
  • Leather Thread Quick Reference Table
  • Leather Thread Types and Variations
  • Leather Thread Characteristics
  • Leather Thread Pros
  • Leather Thread Cons
  • Leather Thread Manufacturing Process – How They’re Made
  • Leather Thread Costs
  • Alternative Options for Leather Thread
  • Experienced Tips for Working with Leather Thread
  • My Personal Research with Leather Thread
  • Leather Thread Care and Maintenance
  • Helpful Leather Thread Insights
  • Key Takeaways
Various Spools of Leather Thread - Leather Thread - Liberty Leather Goods
Various Spools of Leather Thread

Clearing Up Myths & Misconceptions

When first choosing a leather thread, a common concern for most people is worrying about their thread breaking with use. This spirals into new crafters thinking they need the thickest thread possible for every project. While thicker thread may be stronger, it is unnecessary for every project.

Judgment must be used when determining what size to work with. Bags, belts, shoes, and other hardwearing goods that may be under a lot of tension, may require larger sizes. However, wallets, key chains, watch straps, and other low-wear goods can use thinner threads with no fear. 

When You Might Use Leather Thread

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Leather thread is a standard part of leather crafting used in almost every project. While gluing leather pieces together may provide a temporary bond, sewing the leather is almost always necessary to create a more permanent one.

However, a leather thread may also be used as a decorative accent to a leather project. Like embroidery, using leather thread can create a fully stitched project or add a design to a leather project.

Leather Thread Quick Reference Table

CharacteristicDetails
ToolLeather Thread
Component MaterialsPolyester, Nylon, Or Linen
Common Sizes.6mm, .8mm, 1mm
Cost Range ($)$5–$100
Recommended MaintenanceDusted with a fine horsehair brush
Recommended StorageKept on the original spool, and away from heat
Common UsesBonding leather pieces, or decoration
How Long It Lasts (on average)20–50 Years
Leather Thread Characteristics

Leather Thread Types and Variations

Leather thread is widely varied with many companies offering different products. Universal variations are color and size. When picking a thread for crafting, most brands will offer a large selection of colors, and common sizes, including .6mm, .8mm, and 1mm. More significant differences begin with thread material.

Linen is the only common natural material used for leather, as polyester and nylon are artificial. This provides a different look, with the fibers of the linen being visible. The shape of the thread impacts the way the final product will look.

Rounded thread is typically braided fibers, while flat, and bonded, will instead create a single fiber to create the thread. Finally, threads may be waxed or left natural. A waxed thread is said to be more rigid, allowing it to be pulled through stitching holes more easily. 

In this helpful video below by J.H. Leather, Jo discusses different types of leather thread, showcasing the leather thread differences and sizes. 

Leather Thread Characteristics

Materials

Linen is a unique leather thread as it is natural. Its braided fibers provide strength, structure, and size for the thread. The most appealing part of linen thread is its natural look, as the final product has a more subdued finish with tiny fibers visible. A polyester thread is the most commonly found type of leather thread.

A polyester thread is made of thin strands of material that are combined in various ways. Although polyester can be braided to mimic linen thread, the artificial nature of the material will create an unnatural sheen. Nylon thread is similar to polyester but is bonded to create a single strand. Compared to polyester, it has more stretch and is more wear-resistant.

Both polyester, and nylon, can be melted when finishing a stitch to lock the thread in place. In a study at the Faculty of Applied Arts, Helwan University, Cairo, Egypt, Dr.Eman Rafat Saad tested the differences between nylon and polyester thread and found that nylon thread in a sewing machine can sew thin leather without causing the leather to pucker. This is due to nylon’s elasticity. 

Sizes

When choosing a size for leather thread, there are three common options, .6mm, .8mm, and 1mm. In most cases, any thread size can be used, but the smallest size, .6mm, is best suited for more refined leatherwork. It offers smaller stitches that do not overpower a leather piece.

The .8mm thread size is seen in slightly larger goods. Bags, shoes, and rugged belts will use a larger-sized thread. A thicker thread will provide more strength, which may be desirable for specific projects. Thread sizes that are 1mm and above are used for utility purposes.

The thick thread is used on saddles, trunks, and other hard-wearing goods. While most crafters will not require large thread, it may be a popular choice for those looking for a rugged thread.

Variations

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The leather thread’s shape provides a vastly different final look when finished. Round thread, true to its name, will provide the most organic look but may protrude past the surface of the leather. A flat and bonded thread will sit closer to the surface but may not be appealing to some as they stretch to fill the hole they are used in completely. 

Leather Thread Pros

Sewing leather with thread is the most common way to attach two leather pieces permanently. Unlike rivets, the thread can cover the entire border of a leather project, ensuring no area will separate. A leather thread also provides a more professional-looking product, elevating basic leather items to a more refined piece. Leather thread can also be used to add decorative design to a project, allowing for even more personal expression in each project.

While gluing leather pieces together may provide a temporary bond, sewing the leather is almost always necessary to create a permanent one.

Leather Thread Cons

While leather thread is common in leathercraft, the skills required to keep stitching neat are much more difficult. Hand-sewing with leather thread requires specific techniques to keep the thread looking the best.

Unlike lacing, rivets, or glue, sewing a piece of leather takes much more time than any other option. Lastly, threading is the most common place for failure in leather projects. After decades of use, the thread will face abrasion that wears down the fibers until it breaks, requiring replacement.

Leather Thread Manufacturing Process – How They’re Made

Linen thread starts from the fibers of flax plants, which are harvested and spun using industrial machines to create yarn. These strands of yarn are then combined or locked by being braided into each other, with the final product being leather linen thread.

Polyester and nylon, however, are synthetic materials. They are both resins created as an artificial fabric that can be made with a single large strand of material. Alternatively, multiple strands can be used to mimic the look of a more natural thread.

Leather Thread Costs

When purchasing leather thread, the length of the spool determines the price. Small test sizes, such as 25 meters and below, will let crafters test a specific color, size, or thread type without committing to a larger spool. Test spools cost around $5.

Sizes up to 50 meters are more common and suit any crafter who occasionally works on smaller projects. These spools cost $8–$10. A 100-meter spool is the last available size for hobbyists. These suit those working on large projects often or using limited thread types. The 100-meter spools are $18–$20.

Lastly, leather threads can be purchased on a production level in 500 and 1,000-meter sizes. These spools are best suited for those working full-time with leather or hobbyists looking to make a purchase that will last them years. These larger spools can cost $50 and $100, respectively.

Alternative Options for Leather Thread

While sewing leather is the most common way to bond together pieces, other options are possible. For a temporary bond, glue or double-sided tape can work well. Contact cement, rivets, or lacing are the best options for a more permanent bond. Lacing leather together will be the most similar option to leather thread.

Experienced Tips for Working With Leather Thread

  1. Linen threads can be pulled through beeswax to coat them
  2. Artificial threads may need to be pre-stretched to prevent areas from loosening over time 
  3. Tap down the stitches once finished to close the holes and provide a cleaner look
Various Spools of Waxed Leather Thread - Leather Thread - Liberty Leather Goods
Various Spools of Waxed Leather Thread

My Personal Research with Leather Thread

After trying several types of leather threads, I found that I prefer thread that is not waxed. However, when researching leather threads, most crafters suggest a waxed thread, even if you have to apply the wax yourself. As a result, I tested the difference between a waxed and unwaxed thread to see how it changes the thread. I looked at ease of stitching, durability, and longevity. 

Ease of Stitching

Using the same .6mm rounded and unwaxed thread for this research, I applied a large amount of beeswax to one thread and left the other alone. When stitching with both threads, there was no difference to me. Both would go through the leather without any issues. My only complaint with the waxed thread was that the holes would rub off some wax as it passed through, leaving residue on my test piece. 

Durability 

Although I was not going to test durability when I started the research, my unwaxed thread had split fibers after sewing. This caused me to wonder if the wax was helping keep the thread together. To test this, I pushed large needles into both threads to see how they behaved when separated.

The unwaxed thread quickly wanted to split into multiple strands and began to fray as I wiggled the needle around. The waxed thread, however, did not change at all. It was rigid, and the needle parted the thread just the same, but the thread stayed together.

Longevity 

To assess how both threads would last over time, I tested their abrasion resistance by passing sandpaper over the top and noting what happened each pass. The unwaxed thread frayed on the first pass of the sandpaper, leaving the thread fuzzy throughout. By the third pass, small strands of the thread were beginning to separate, having been worn off.

Finally, some of the thread had torn at the fifth pass of the sandpaper. With the waxed thread, the first two passes did not seem to change the thread at all. However, the third pass pulled up a few fiber strands, similar to the unwaxed thread. The wax thread remained unbroken until the seventh pass of the sandpaper, outlasting the unwaxed thread.

Conclusion

After testing the different threads, it was clear that a waxed thread proves to be stronger overall. It did not fray nor tear as easily as the unwaxed one. However, excessive wax left residue on the surface of the leather, and I can see how that can cause issues for some. As a result, I believe finding a minimally waxed thread or lightly waxing thread yourself is the best option.

Leather Thread Care and Maintenance

How to Clean a Leather Thread

The best way to clean leather thread is to use a small brush to clean off the dust and debris. As you condition or clean the entire leather item, you can also use that as an opportunity to clean off the thread. However, there is no real way to clean stained thread. 

How to Maintain a Leather Thread

To maintain leather thread, it should be kept away from abrasive surfaces. If the thread becomes loose, it can be tapped back down to keep it from snagging. When working with synthetic leather threads, a torn thread can be melted to prevent the other stitches from coming out, prolonging the life of a leather item.

How to Store a Leather Thread

Leather thread should be stored on their spools, tightly wound to prevent tangles. The spools themselves can be placed almost anywhere as long as they are away from heat. Some leather threads, however, will have ultraviolet properties and need to be stored according to their directions.  

Helpful Leather Thread Insights

What thread do you use for leather?

Leather thread is most commonly linen, polyester, or nylon that is waxed to provide strength. These threads work best for hand sewing as they do not fray easily. They also are stronger than other threads, such as cotton or silk.

What is the strongest thread for sewing leather?

Synthetic threads like polyester or nylon are the strongest threads. When used with a larger thickness, both threads will last decades. Polyester and nylon provide nearly 15 pounds of tensile strength and have some elastic properties to prevent tearing.

What weight thread should I use for leather?

The project and the purpose of the thread should determine the thread size. Thinner threads .6mm and below will be well suited for smaller projects like wallets, but as the weight load of the projects increase, so should the thread thickness. 

Why is waxed thread used with leather?

Wax thread provides a more rigid, wear-resistant product. This is especially beneficial when hand-sewing leather, as the rigidity keeps the thread fibers from separating. Waxed thread can also protect the color of the leather thread from fading as quickly.

What is waxed leather thread?

Waxed leather thread is a thread that has had a coat of beeswax, or other wax, applied to the surface. This provides various benefits to the thread, including durability and rigidity. An unwaxed thread can be waxed at home by passing it through wax before beginning to sew.

Can I use upholstery thread for leather?

While other threads, such as upholstery, will work for sewing leather, there are better options. Threads not suited for leather may not provide the same strength as those designed for specific use. 

What is the best leather thread size for a leather wallet?

There is no best thread size for leather wallets, but your desired look dictates choices. A refined and more luxurious wallet will stick to thread sizes .6mm and under. However, those wanting a more rugged look can use larger thread sizes. It is important to experiment with thread sizes to find the look that works best for you. 

Key Takeaways

  1. There is a wide variety of choices when choosing a leather thread. Experimentation is necessary. 
  2. Unwaxed thread can be waxed at home with beeswax.
  3. Thread sizes play a significant role in the look of the outcome. Larger threads are more rustic.

In Closing

Working with leather leads to endless creativity, and thread choices are no different. From size, shape, color, and material, threads can differ in various ways. When necessary, try multiple threads to discover what looks best to you and what is best to work with. 

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