Threads are a very important part of leathercrafting for two main reasons.
First – they hold the product together.
Second – they give the product a premium and distinct look – an unmistakable proof of a fully handmade, hand-sewn item.
At KOVACS Leathercraft, we choose only the best materials from the best manufacturers. Thread choice is no exception. Our work relies exclusively on two exceptional brands: Fil Au Chinois from France and MeiSi from China.
*Threads by MeiSi displayed. Threads by Fil Au Chinois have mostly the same color range.
**There is a color issue when displaying the swatches in Dark Mode in Samsung Internet Browser on Android based devices. Samsung Internet Browser forces Dark Mode by changing all the colors including the colors of swatches displayed. This cannot be resolved by website coding. For this reason if you use Samsung Internet Browser, switch to Light Mode for the most accurate color representation.
No matter which one you choose, you’re getting the best thread available on the market.
We love working with Fil Au Chinois – a waxed natural linen thread, traditionally used by the world’s finest ateliers and by some big brand names that still care about quality. The special feature of this thread is that, when hammered down, it lies completely flat – giving every stitch a subtle, elegant finish.
MeiSi is our first choice when it comes to artisan-level craftsmanship because of how well it is made. We think that MeiSi is slightly superior to Fil Au Chinois in precision, but that perfection takes its toll on the look. For some reason, the small natural irregularities of Fil Au Chinois tend to feel more appealing to the human eye, giving it a slightly more “crafted” and luxurious feel than the flawless thread of MeiSi.
Both are exceptional. The more meaningful decision however lies not in brand, but in material.
There are two types of threads we use in leathercrafting – linen and polyester. Now you may ask, “Which thread is better?” or “Which one should I choose?”. There’s a short answer and a long answer to that question.
Choose linen thread if: you prefer a natural, premium aesthetic, timeless appeal and more organic feel, making it the prime choice for wallets, card holders, passport covers, or journals where maintenance is expected.
Choose polyester thread if: your priority is functionality, longevity, and high stress resistance – especially for outdoor items like saddles or dog leashes – and premium appearance is not your primary concern.
The answer is not simple, because each thread type has unique properties, pros, and cons. Both have their place. Let’s see how they differ.
Pros:
Natural Aesthetic: Offers a premium, natural, and elegant look. Can be hammered down, emphasizing its refined appearance.
Non-Stretching: Very strong and does not stretch, ideal for tight, stable stitches on wallets or visible seams on bags and briefcases.
Biodegradable: A completely sustainable, eco-friendly choice. Made from 100% natural linen and waxed with beeswax. It doesn’t get more natural than this.
Cons:
Less Durable: Weaker than polyester and prone to breakage under heavy use.
Moisture Absorption: Absorbs moisture, which can lead to fraying if not waxed. All our linen threads are waxed and re-waxed every 20 stitches, so this is not a concern.
Requires Waxing: Needs waxing to prevent fraying, add strength, and improve stitch lock.
Limited Colors: Usually available in fewer color options.
Best For: high-end leather goods, bookbinding, and projects where a natural, organic look is desired and the item will be cared for. Especially by means of touching, caressing, or visual appreciation and from time to time, a little leather conditioning.
Polyester thread is stronger, more UV- and water-resistant, and ideal for outdoor or heavy-duty items. Choose polyester for function and longevity, and linen for a premium look.
Pros:
Strength & Durability: Exceptional strength and high tensile capacity for lasting seams.
Resilience: Resists moisture and UV rays, maintaining strength and color in harsh conditions.
Colorfast: Retains color over time.
Cons:
Environmental Impact: Non-biodegradable, as it’s a plastic-based material.
Aesthetics: Can have a slight sheen that doesn’t suit all natural finishes.
Best For: handbags, outdoor items, dog collars, and any project designed to withstand the test of time and the elements.
To put durability into perspective, here’s how both threads perform under stress testing:
Tensile properties of a single yarn (SGS test report)
MeiSi M60 0.65 mm linen thread
17 lbf / 23.05 Nm / 2.35 kg/m
XianGe #15 0.60 mm polyester thread
26.9 lbf / 36.47 Nm / 3.72 kg/m
These values represent the mean breaking force for a single thread. That means five loops can literally lift and hold a 12 kg (25 lb) kettlebell. Now imagine a wallet stitched with 25–30 stitches per side – you’re more likely to tear the leather before the thread breaks. Moreover, all our products are saddle-stitched, which means doubling the holding power through an interlocking knot concealed within the leather.
We build pieces meant to be repaired, not replaced. We truly believe that products built to last for decades have lesser environmental load than the ones that fall apart in two years.
We build pieces meant to be repaired, not replaced. We truly believe that products built to last for decades have lesser environmental load than the ones that fall apart in two years.
For this reason, even though we strongly advocate sustainability within our core values and recommend linen threads, the best practice is to choose the right thread for the job, which often means using both.
For visible stitches that define the premium look and feel, we always choose linen thread. For all small leather goods, we strongly recommend full linen.
For hidden stitches, and especially those requiring structural durability, we choose polyester. This is especially recommended for big pieces like duffle bags or briefcases, that expect to carry heavy goods and many files.
Why? Because the synthetic fiber content in polyester thread is so minimal that the product’s improved durability and lifespan far outweigh its drawbacks, resulting in a significantly lower environmental impact through reduced waste. Reparability ensures each piece can live, be repaired, and continue its story for generations – as a true heritage.