Threads for Shoemaking
Threads for shoemaking ensure durable, strong seams in footwear. Choices range from nylon and polyester to waxed linen, each tailored for specific leatherworking needs.
Thread size and relationship between leather thickness and needle size.
Before diving into the various types of threads, it's crucial to have a foundational understanding of thread sizes and how they're represented. While some sources indicate the thread's diameter (e.g., 0.6mm), others may use a designated thread number. Establishing a clear relationship between leather thickness, needle size, and thread diameter is essential for seamless sewing, ensuring neither the material nor the machine is damaged in the process.
When dealing with leather that has a thickness of 0.9-1.1mm, commonly used for most men's and women's ellgant/cassual shoes, the recommended needle sizes are 85/13 to 90/14 (following the European sizing system). To pair with these needles, the advised thread sizes fall within the Tex 25 to Tex 30 range.
To demystify the Tex system: the Tex number indicates the weight of 1,000 meters of thread in grams. For instance, a Tex 25 thread typically equates to a diameter of roughly 0.25mm. Thus, for leather with a thickness of 0.9-1.1mm, one should ideally use:
Needle Size: 85/13-90/14
Thread (NeB) Size: 60 (or equivalent to Tex 25-30)
Thread Diameter: 0.25-0.30mm
Thread Sizing Systems
Denier and NeB (Number English Bonded): In these systems, a higher number indicates a finer, thinner thread. For instance, NeB 80 is thinner than NeB 60.
Tex System: Unlike the Denier and NeB systems, a higher Tex number indicates a thicker thread. The Tex number signifies the weight (in grams) of 1,000 meters of thread. Therefore, a heavier (and thicker) thread will have a higher Tex number.
By this understanding, Tex 25 (0.25 mm) is roughly equivalent to NeB 60. Conversely, a finer thread like NeB 80 might align with Tex 15 or Tex 20.
However, for those considering a thread with a 0.6mm diameter, be prepared to adjust needle sizes accordingly. A thread of this thickness pairs better with larger needles, potentially in the 100/16 to 110/18 range or even above.
Armed with this knowledge, you'll be better equipped to select the right thread and needle combination, ensuring your shoemaking project is executed flawlessly.
Bonded Polyester Thread
A popular choice for its high tensile strength, polyester thread is resistant to ultraviolet (UV) rays, mildew, and most chemicals. It also retains color well, making it a go-to for shoes that demand both durability and aesthetics.
Bonded Nylon Thread
With high elasticity and strength, nylon threads are particularly suited for areas of the shoe that experience significant stress, such as seams. However, they're more prone to UV damage than polyester threads.
When determining the ideal thread for shoemaking, there isn't a one-size-fits-all answer between nylon and polyester. The choice largely hinges on the specific requirements of the footwear. Athletic shoes, or those that need added flexibility at the seams, might benefit from nylon. Conversely, for outdoor footwear or shoes that demand resilience against environmental factors, polyester might be more apt.
Below are the advantages and disadvantages of both thread types to consider in your shoemaking craft:
Nylon Thread:
Elasticity: Nylon thread offers superior elasticity, making it particularly suited for areas of the shoe that experience significant flexing or stress, such as seams.
Strength: Nylon boasts a high tensile strength, which means it's resistant to breaking under tension.
Smoothness: Due to its smooth surface, nylon thread can produce clean, tight stitches.
UV Sensitivity: One of the drawbacks of nylon is its sensitivity to ultraviolet (UV) light. Over time, prolonged exposure can cause it to degrade or discolor.
Melting Point: Nylon has a lower melting point than polyester. While this is rarely an issue in most shoemaking contexts, it's something to consider if the shoes will be exposed to high temperatures.
Polyester Thread:
UV Resistance: Polyester thread is more resistant to ultraviolet (UV) rays compared to nylon. This makes it a better choice for shoes that might be frequently exposed to sunlight.
Resistance to Elements: Polyester is generally more resistant to moisture, mold, mildew, and chemicals than nylon.
Durability: While both threads are durable, polyester's resistance to environmental factors gives it a slight edge in long-term durability in certain contexts.
Consistent Color Retention: Polyester thread tends to retain its color better over time, making it less prone to fading.
Heat Resistance: Polyester has a higher melting point, making it slightly more resistant to heat compared to nylon.To all my students I recommend to use polyester threads and in all my shoemaking courses this is the thread that I use too.
Linen Thread
Linen thread is derived from flax plant fibers. In its raw form, it remains uncoated and untreated. To make it suitable for shoemaking, it's essential to thoroughly coat the entire thread with beeswax. This treated linen thread is predominantly used in welted shoe constructions and other hand-stitched methods, like stitch down construction we do Dr Martens Boots or Opanka shoe sole construction in Bespoke Opanka Handsewn Shoe Course.
Waxed Threads
Ideal for hand-stitching, waxed threads glide smoothly through leather or other materials, creating even stitches. The wax coating also adds a level of water-resistance to the stitch.
Kevlar® Thread
Extremely strong and heat-resistant, Kevlar® threads are often used in safety footwear or shoes meant for extreme conditions.
Online shoe making stores
There are few stores for shoemaking, and here are a few where you can find some of these threads. Additionally, I'd recommend checking out local stores in your area.
https://www.abbeyengland.com/workshop-materials/thread/
https://www.buckleguy.com/Search.html#/Search.html?search=thread