Leather Grading & Glossary of Tannery Terms

How is Leather Graded?

A common misconception is that the grade of the leather refers to its quality. All of our leather at Hermann Oak is tanned uniformly in the same tan yards meaning there is no difference in the actual quality of the tannage between A-grade and D-grade. What does change, however, is the yield which is heavily dependent on the size and type of product being made.

Leather is a natural material, which means that each piece has unique qualities from the animal it came from, such as bug bites, stretch marks, or scars. Additionally, leather can have minor defects, such as butcher marks or holes which originate in the hide take off process at the packing houses before the hide reaches our tannery.

Yield refers to the idea that if someone were only cutting belt blanks from a side of leather, one side of Grade A might yield 20 belt blanks. In contrast, a side of Grade D might only yield 15 belt blanks due to imperfections that may make 5 of those strips unusable. Keep in mind that in this example, the type of belt being made, ie. tooled, stamped or natural, will impact that yield assuming small imperfection can be hidden with tooling, stamping or dye work.

For leatherworkers building knife sheaths, holsters or smaller items, higher frequency of blemishes, brands or butcher cut will have as great of an impact on yield as these are more easily cut around for small items such as wallets, watch straps etc. Similarly, light fat wrinkles can be usable by leather crafters who plan to condition or "glass slick" the leather as the wrinkles would be less pronounced once the leather is compressed and then tooled or stamped. C-grade or D-grade might work for someone in either scenario.

A- Grade leather however, is a great option when making handbags, chaps or items requiring large panels of clean cutable leather.

Again, the grade of the leather does not define the quality of the leather itself, but rather its cosmetics and how that might impact the amount of product that can be produced from that hide.

Grading Considerations

A or #1 —— Very few cosmetic blemishes or holes outside of prime.
B or #2 —— Contains a few defects. No brands.
C or #3 —— Contains more defects. Generally not good for plain belts.
D or #4 —— Can have large brands and/or holes and other damage.
Branded —— Hand sized brands. Otherwise graded as above.
Job Lot/3X —— Lowest grade of leather available. High volume of grain damage typically used for filler or les visible areas of leather products.

What is the difference between a Grade-A hide and a No. 1 saddle skirting hide?

Sometimes our grading system can seem a little confusing, with many leathers coming in grades of A, B, C & D while saddle skirting is graded as a #1, #2, #3 & #4.

Fundamentally, they are very similar in that D grade and #4 will exhibit the highest volume of grain damage, C-grade and #3 will exhibit less and so on as you increase in grade. However, there is one key difference.

If you are making leather holsters, portfolios, or knife sheaths, it’s likely that you are taking the same pattern and repeating it over and over, positioning it to get the maximum yield from that piece of leather. Because of this, the side of leather is graded as a whole with the prime area, defined as the bend, being most critical but not the only area factored into the grade.

Skirting, however, is predominantly used by saddle makers. When evaluating skirting, a very specific set of criteria is used based on the most common use of this leather to make saddles. Specific parts of a saddle come out of the same place in the side every time because those areas of the side have a suitable hide structre for each respective part of the saddle.

For instance, the biggest piece on any saddle is generally the seat. This will typically come out of the butt of the side which is the back half of the bend nearest the tail of the animal. Grading is largely focused on that specific region of the hide, rather than evaluating the leather equally throughout to ensure a saddle seats and other parts can be cut from the higher grade sides.

Hermann Oak Glossary of Terms

A–C

A/B/C/D Grades: Grades assigned to leather based on grain damage and yield expectations . “A” is highest, “D” is lowest.

Brands: Markings that are made either using heat or chemical treatment to the cattle while in the fields. Typically located in the back half of the animal near the butt. Can range from baseball to basketball sized usually resulting in 1 sq foot of lost cutting area.

Buffing: The process of sanding or smoothing the flesh side of leather to improve feel or visual appearance. Common in roughout saddles.

Butcher Cuts: Deep cuts caused during take off of the hides at the packing house. Can lead to visible holes or indentations that often impact yield of larger panels or strap goods.

Carving/Tooling/Strap/Holster Leather: Different terms for the same type of vegetable-tanned leather, based on how the leather will be used. Hermann Oak defines all of these types under our Strap Leather.

Chrome Tanning: A fast and effective leather tanning process using chromium salts. Cheaper and more common. Chrome tanned leather are commonly used for furniture, clothing, footwear and auto upholstery. Chrome tanned leather is water resistant and as a result does not offer the tooling qualities of vegetable tanned leather as water absorption is necessary for tooling, stamping and carving. Chrome tanned leathers are estimated to make up nearly 90% of the total annual leather production.

Corium: The lower layer of the hide beneath the grain, providing structural support. Rich in cross-linked fibers.

D–F

Drum Dyeing: A method where leather is dyed in large rotating drums. Standard drum dyeing typically dyes the surface; struck-through dyeing penetrates fully.

Enamel Layer: A natural protective coating beneath the epidermis. Our preserves this in during the un-hairing process which results in improved performance in dyeing, burnishing, and stamping performance as well as helping enhance the natural patina of the leather over years of use.

English Finish: A hand-applied conditioning process that enhances a leather's appearance.

Epidermis: The outermost skin layer that is removed during tanning to expose the enamel and grain.

G–L

Grain Side: The smooth outer surface of the leather (the animal's hair side), valued for stamping and burnishing.

Job Lot / 3X: Terms for the lowest-grade leather available, often used for filler or low-visibility applications.

Latigo: Traditionally, a chrome-tanned and veg-retanned leather used for straps and tack. Hermann Oak makes 100% vegetable-tanned latigo, resulting in a firmer feel.

Mossing/Pasting: Applying a sealing finish to the flesh side to prevent peeling or fuzzy texture, often used for belts and unlined holster leathers.

P–S

Pickling: A chemical process used by nearly all Vegetable tanneries involving salt and acid baths (often with sulfuric acid) to speed up tanning. Hermann Oak Leather is not pickled, which takes longer to produce, but creates a leather with unique characteristics our customers demand.

Plug Leather: Filler leather made from damaged hides, suitable for use in hidden or structural applications. See Job Lot/3X.

Racetrack: A process where leathers are dipped to add more oils, resulting in a darker, heavier, and weather resistant product used in Tack and Rein making. Often seen as an additional process applied to Hermann Oak Harness leather.

Setting Machine: Equipment used to soften stiff leather after processes like Harness or racetrack leathers.

Single Bend: A cut of leather derived from the butt section of the hide, excluding the belly and shoulder, known for high yield in belt making.

Skirting Leather: A specific type of leather used in saddle making, graded on a 1–4 scale, separate from the A–D strap grading system.

Splitting: Leveling leather to a desired thickness with a highly technical machine that removes the flesh side from the grain side. We use a full side splitting machine as compared to smaller units maxing out usually around 20-30 in width available for shop use commonly referred to as band knife splitters.

Strap Leather: General term for vegetable-tanned leather used in belts, tooling, and holsters; also referred to as holster leather, carving leather, and tooling leather.

Struck Through (Fully Penetrated): A leather dyeing process where dye penetrates through the entire thickness, reducing the need to edge-dye cuts.

T–Z

Tannery Run (TR): A mixed-grade selection of leather (typically A/B/C) targeting a "B" grade average. Grading varies by leather type. In an ideal scenario, this would mean 25% A-grade, 50% B-grade, and 25% C-grade, but it can vary.

Unfinished: A harness leather sold without lacquer finish so customers can apply their own oils or finishes.

Unsplit Flesh Side: A fuzzier and softer interior surface of leather when left unsplit.

Vegetable Tanning (Veg Tan): A traditional tanning method using plant-based tannins like quebracho and wattle. More environmentally friendly than chrome tanning.

Wattle/Quebracho Extract: Primary tannins used in Hermann Oak's veg tanning process. The tannin-rich qualities of Quebracho were discovered in the 1800s, and it has since been sustainably harvested from century-old trees in Argentina to produce the highest-quality leathers in the world. Wattle is a natural tanning agent harvested from the bark of the Acacia Mearnsii tree on plantations in South Africa.