Leather/Workshop Lexicon
In this leather lexicon I explain the technical terms of traditional fine leatherwork that are used in my Munich studio – from vegetable tanning to the wrapping technique.
Impact (Technique)
Definition: A folded edge refers to the precise folding over of a previously thinned leather edge to create a neat and durable finish to the workpiece. The C. Sturm Standard: In our workshop, every edge to be folded is first thinned by hand or with a skiving machine. This thinning of the flesh side is essential to ensure that the edge doesn't protrude after folding and that the workpiece retains its elegant, flat silhouette. We perform this process with the utmost dexterity, as the folded edge often has to simultaneously secure the lining and the stiffening material. Advantage for the customer: A folded edge is significantly more durable than a simple edge finish. While edge finishes can become brittle or flake off over time due to movement and weathering, the folded edge is firmly attached to the body of the piece by stitching, providing a natural, tactilely pleasing finish that remains dimensionally stable for decades.
Alran Chèvre Sully (Goatskin)
Definition: Goatskin leather, also known as "Chevreau," is considered one of the finest materials in the world of fine leather goods, prized for its delicate grain and exceptional toughness. The C. Sturm Standard: We primarily use this high-quality goatskin leather for fine accessories and as luxurious linings. Despite its thinness, it is more tear-resistant than many types of cowhide while remaining exceptionally supple. Its characteristic, slightly pearly grain (pore pattern) gives the pieces an exclusive texture. Benefit for the customer: Chèvre Sully combines lightness with a robustness that is hard to imagine in such a fine leather. It is water-repellent and less prone to scratches than smooth calfskin, allowing the product to maintain its flawless, luxurious appearance even with daily use over a long period.
Hand sewing vs. machine sewing
Definition: While machine stitching is done with top and bottom threads using specialized sewing machines, traditional hand stitching is done with two needles and a secure saddle stitch. The C. Sturm Standard: The choice of technique depends on the product's intended use and design. We use hand stitching specifically where the highest structural integrity is required, such as on handles or heavily stressed edges. For precise decorative seams and large-area joins, we use our specialized fine leather sewing machines, which guarantee an absolutely uniform stitch pattern. Advantage for the customer: Hand stitching offers maximum security: Should a thread break, the seam will not unravel because each stitch is individually knotted. Machine stitching, on the other hand, allows for a delicate aesthetic and precision that creates an elegant, understated look for very fine leather goods. In both cases, we guarantee durability far exceeding industrial standards through the use of the highest quality threads.
Sharpening
Definition: Skiving is the manual or machine thinning of the leather edge from the flesh side to selectively reduce the material thickness. The C. Sturm Standard: In our workshop, skiving is the essential prerequisite for a perfect hem. Only by precisely skiving the edges, often to a razor-thin degree, can the leather be folded so that the edge doesn't add bulk and the piece retains its elegant, flat shape. We perform this step with the utmost dexterity, as an edge skived too thin loses stability, while an edge that is too thick would make the hem appear uneven. Benefit for the customer: Expert skiving creates transitions that are virtually imperceptible to the touch. It enables a durable hem that sits flush with the lining leather, minimizing friction points and ensuring the product retains its sophisticated silhouette for decades.
patina
Definition: Patina refers to the elegant sheen and distinctive changes in color and surface that high-quality leather develops over time through natural use. The C. Sturm Standard: We preferentially use open-pored, vegetable-tanned leathers, as only these are capable of developing a genuine, deep patina. For us, patina is not a sign of wear, but rather proof of the material's vitality and quality. A unique interplay of light and shadow develops over the years, especially along the edges protected by the edging. Benefit for the customer: A product with patina doesn't age, it matures. It tells the story of its owner and becomes more valuable and personal with each passing day. Because the edging protects the mechanically stressed edges, the structural integrity is preserved, while the surface gains aesthetic depth.
Saddle transformation (upcycling)
Definition: The repurposing of leather from historic saddles with damaged trees into new, fine leather goods. The C. Sturm Standard: A broken saddle tree renders a saddle unusable for equestrian sports, as it forms the saddle's "skeleton." However, the leather, carefully tended over decades, is a precious raw material. We "rescue" this heritage leather and transform it into new products. Thanks to its existing, deep patina and the extreme density of the fibers resulting from previous use, this leather offers a feel that cannot be replicated with new material. Benefit for the customer: The customer receives a piece of living history. This upcycling is not only sustainable, as a valuable by-product is preserved, but it also results in unique pieces with exceptional durability and a character that can only develop through decades of use. Our unique weaving technique gives this historically significant material a new, elegant form.
Leather care & longevity
Definition: Leather care refers to the conscious preservation of the natural material properties through expert cleaning, conditioning, and protection from extreme environmental influences. The C. Sturm Standard: In our workshop, we follow the principle "Less is more." A high-quality product with a precise hem often requires only minimal care, as the delicate edges are mechanically protected. We recommend only natural oils or waxes specifically formulated for the tanning process to ensure breathability. However, the most important "care" is regular use and movement of the leather, which keeps it supple. Benefit for the customer: With proper care and the inherent advantages of the hem, the leather not only ages but also "matures." It remains tear-resistant and supple for decades, while the structural integrity of the handcrafted construction ensures the long-term value of the piece.
Full grain leather
Definition: Full-grain leather refers to the uppermost, most valuable layer of the hide, whose natural grain pattern has neither been sanded nor embossed. The C. Sturm Standard: For the C. Sturm Atelier, full-grain leather is the indispensable foundation. Only this leather possesses the full density of its fiber structure, allowing us to trim the edges to the absolute limit for an extremely flat hem without compromising the edge's stability. It represents the top 5–15% of global leather quality. Benefit for the customer: Full-grain leather is the most durable and breathable type of leather. Combined with the hem technique, it creates products of exceptional longevity that do not fray and develop a deep and beautiful patina over time.
Semi-aniline leather
Definition: Semi-aniline leather is drum-dyed leather that receives an additional, ultra-thin pigmentation on the surface for a more uniform color and enhanced protection. The C. Sturm Standard: We select semi-aniline leather for pieces that are exposed to higher levels of wear and tear from light or dirt in everyday use. Because the natural grain remains visible through the light finish, it retains its luxurious character. When skiving the edges for the hem, we take care to ensure the finish doesn't crack, which underscores the high quality of our raw material. Benefit for the customer: This leather offers the perfect balance between the refined feel of a natural product and the easy care of a protected material. It is more lightfast than pure aniline leather and can withstand a rain shower or careless handling without immediately staining.
Vegetable tanning
Definition: Vegetable tanning is a traditional, time-consuming process that uses natural tannins from bark, wood, or fruit to preserve the hide. The C. Sturm Standard: We prefer vegetable-tanned leather because of its excellent structure and malleability. This type of leather "remembers" the hand-crafted processing: Once folded and sewn, it retains its shape for generations. Furthermore, it is the only tanning method that develops a truly authentic patina. Benefit for the customer: Vegetable-tanned leather is sustainable, skin-friendly, and often biodegradable. It is an honest material that improves with use and, due to its firm structure, is particularly stable and durable.
Overview of other tanning methods
Definition: In addition to vegetable tanning, specialized processes exist such as chrome tanning, chamois tanning (oil tanning), and combined methods. The C. Sturm Standard: We employ these processes selectively according to technical requirements: Chrome tanning: When extreme softness, elasticity, and water resistance are required, for example, for fine nappa leather used in linings. Chamois tanning (oil tanning): An ancient process using fish oil that produces leather of exceptional softness and absorbency. Combination tanning: Combines the softness of chrome tanning with the richness and durability of vegetable tanning, ideal for modern luxury accessories. Advantage for the customer: The variety of tanning methods allows us to select the technically perfect material for every component – from the sturdy body to the supple lining. In all cases, we ensure that the leather meets the high standards for skiving and finishing to guarantee the proverbial C. Sturm durability.
Ethical material sourcing & upcycling
Definition: Leather is one of humanity's oldest upcycling materials, as it is derived from hides that are an unavoidable byproduct of the food industry. Without the skilled work of tanneries, these valuable organic resources—approximately 7.3 million tons annually—would have to be disposed of unused in landfills, resulting in significant environmental damage. The C. Sturm Standard: We see ourselves as custodians of value, giving this precious raw material a second life, often lasting decades, through the highest level of craftsmanship. In our workshop, we exclusively process hides from farm animals such as cattle, sheep, or goats that are a byproduct of food production, and we strictly reject leather from farms that primarily raise animals for hide production (e.g., many exotic leathers). Through masterful techniques such as the tacking and precise edge trimming, we ensure that the natural robustness of full-grain leather is preserved in a product that will last for generations. The advantage for the customer: The customer acquires an object with a clear conscience, one that inextricably combines ecological responsibility and timeless luxury. Because we forgo short-lived industrial standards and instead focus on extreme durability and repairability, the ecological footprint of each individual piece is significantly reduced over its entire lifespan. A C. Sturm product is not a fleeting consumer item, but a lasting companion whose character steadily deepens with the patina that matures over the years.