A Guide to Advanced Leathercraft: Stitching Chisels
The stitching chisel is the most frequently used tool in handmade leathercraft; no leather project can be completed without one. Most people view the chisel as a rather mundane tool—often less noteworthy than the cutting knife—simply buying and using it without much thought. Many crafters with years of experience still limit their understanding to the basic diamond-shaped chisel. Today, I will provide a detailed explanation of the different types of chisels and the nuances of using them.
I. Diamond Chisels
The diamond chisel is invariably the first type a leathercrafter encounters; in fact, it was the only type available in the domestic market during the early days. Popular brands include Japan’s CRAFT, ELLE, and Iwataya. There are also numerous domestic replicas—"Piao Yinxiang," for instance, produced two versions based on the ELLE design. As for the ubiquitous "white steel" diamond chisels found everywhere today, specifications vary so wildly between manufacturers that direct comparison is impossible.
The reason for this prevalence is simple: beginners typically start with vegetable-tanned leather. The techniques are straightforward, and achieving good results is relatively easy; unless one attempts leather carving, the costs and difficulty level remain manageable. The diamond chisel is essential for working with vegetable-tanned leather. Using "European-style" chisels (pricking irons) on this type of leather is difficult because the resulting stitch holes are too small. Consequently, until a crafter reaches a certain level of proficiency, the diamond chisel remains indispensable for vegetable-tanned leather projects.
Diamond chisels fall into two categories: blunt-tip and sharp-tip. Let’s look at the blunt-tip version first.
Blunt-tip chisels are the most common type in the domestic market. They feature a slightly rounded tip; when punching through, they create a larger exit hole on the back of the leather, which facilitates stitching, though the process requires significant physical force. Iwataya’s blunt-tip chisels are among the most famous examples.
Now, let’s look at the sharp-tip version.
Sharp-tip chisels are relatively rare in the domestic market. Beginners often mistake them for simply being a different level of polish, but they are actually a distinct type of chisel. They offer superior penetrating power and are generally suited for thicker Japanese-style leather goods. They produce cleaner exit holes with less fraying compared to blunt-tip chisels, and the hole shape is more precise. However, due to the angled design of the cutting edge, even a slight relaxation of the wrist can cause the chisel to punch crookedly—sometimes significantly so. They are considered advanced tools that are challenging to master. Domestically produced "white steel" diamond stitching chisels are also usable; however, due to precision issues, the punched holes often exhibit slight irregularities in shape (see the image below).
Generally, the holes made by a diamond chisel should have neat corners and sides of equal length. Some makers currently elongate the top and bottom edges of the holes to mimic the stitch appearance of European-style chisels; while this looks effective at first, the area around the hole tends to get dirty quickly after use. In a proper stitch, there should not be a large gap between the threads entering and exiting the hole.
The traditional procedure for using diamond chisels involves several steps, though few people follow such a laborious process. Most crafters skip steps two and four—or even step one—entirely. However, for the best results, it is recommended to carry out steps one, three, and four.
Diamond chisels can also be used on soft leather, though the resulting holes will be larger. By choosing a smaller chisel, however, one can still achieve ideal stitching results on soft leather.
II. Flat Chisels
Flat chisels are used when creating special effects, stitching with leather thongs, or when one's punching precision is lacking. Standard flat chisels are uniform in design, so—aside from the spacing—there isn't much to consider when selecting one.
Specialized flat chisels do exist but have limited applications and usually require custom ordering.
Large flat chisels are also used when cutting card slots.
There is only one important point regarding flat chisels: the cutting edge should not be sharpened to an extreme point. If it is too sharp, the hole on the back becomes a mere slit, making the actual stitching process very difficult.
III. Angled Flat Chisels
Before "olive-style" chisels arrived in mainland China, there was a period when a so-called "premium" chisel—the angled flat chisel—was highly popular and considered far superior to the diamond chisel. At the time, it was referred to as the "European chisel" (or "Euro-chisel"), and some even tried to pass it off as the "French chisel." Its popularity was short-lived, however; the subsequent arrival of olive-style chisels completely eclipsed it.
Angled flat chisels are considered entry-level European-style chisels—similar to blunt-tipped diamond chisels—and are very easy to use. In fact, they are arguably better suited for crafters who are just starting to work with soft leather. Let’s take a closer look at the details of the angled flat chisel. The standard slanted flat-blade stitching chisel is shown below; if driven too deeply, it stretches the hole, resulting in uneven stitching—this is the primary drawback of this type of chisel.
Blanchard actually produces slanted flat-blade chisels as well; it is a misconception that Blanchard chisels are exclusively high-end products.
Details and punching results of a high-quality slanted flat-blade chisel are shown below; the blade tip is crafted to be very narrow, preventing it from stretching the hole. The cutting edge is curved, which reduces the stress on the blade and makes it less prone to breakage. However, there is a downside: if too much force is applied, it drives in very deeply, making it difficult to extract.
The stitch holes created by this chisel are long, making it easy to achieve a wavy stitch pattern, though the spacing between the entry and exit points is wider. Additionally, the holes are rectangular; if the stitching is tight, long-term use can cause the holes to stretch and enlarge. This is a common flaw shared by this category of chisels.
Blanchard once released a rather unconventional design that was convenient and fast to use; although it was limited to thin, stiff leather and is no longer available for purchase, I am including an image of it here.
IV. Hexagonal-Blade Chisels
(Images for this section were difficult to find, so I took my own explanatory photos; please excuse the image quality.)
The so-called "French-style chisel" is actually a hexagonal-blade chisel. It gained fame because it is used on high-end handmade leather goods—such as those from Hermès—and serious craftspeople usually own several sets with varying stitch spacings.
The blade has a hexagonal cross-section with tiny angled flares at both ends of the stitch hole, preventing the hole from deforming over time. This is why it is the standard choice for high-end leather goods. However, a brand-new chisel cannot be used immediately because the factory-set hole width is often unsuitable. There are subtle differences in hole length across various European schools of thought—English, French, and Italian styles all feel distinct—so one must manually refine the chisel teeth rather than using them straight out of the box. The image below shows a chisel I use personally; you can see the shape resulting from the manual refinement and the French-style tooth width. European-style leatherwork demands strict precision regarding the width of the stitching chisel's teeth; consequently, the cutting edge often needs to be narrowed during the sharpening process. For the demonstration photos, I used vegetable-tanned leather; the slight deformation of the stitch holes occurred because I tend to apply force to the left side when withdrawing the tool—an issue that does not arise with soft chrome-tanned leather. The hexagonal shape of the stitch holes is clearly visible. These are macro shots; a strand of hair is included for scale.
This is what the stitching typically looks like on soft leather. In this macro shot, the spacing between the entry and exit points of the thread is 0.4 mm.
Three commonly used stitch spacings: 2.7 mm (for watch straps), 3.38 mm (for wallets), and 3.85 mm (for large bags).
A comparison of French-style and English-style tooth widths reveals that the French-style cutting edge is slightly smaller. Italian-style teeth share the same width as English-style ones but feature thicker blades, so there is no need to reduce the blade thickness during sharpening.
Finally, regardless of the style, it is best for the chisel to have the highest possible hardness.
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