Learn About Leather

Learn About Leather

Leather Terminology

  • Chrome-tanned - Leather preserved with chromium compounds and other mineral agents to produce supple leather for garments, shoes and gloves.
  • Vegetable-tanned - Leather preserved with tannins from bark, seeds, and wood to produce strong and slightly stiff leather for luggage and belting.
  • Drum dyed - Leather dyed in a rotating drum until the dye completely penetrates the leather.
  • Aniline - Leather dyed with transparent aniline dyes to produce a beautiful transparent finish and suppleness. No pigment is used, but a light finish may be applied to color or protect the leather.
  • Semi-aniline - Aniline dyed leather topped with a very light coat of pigment and finish to even out the color and increase durability.
  • Pigmented - Leather coated with resin containing pigment. Pigment gives leather a uniform color and shade. Low-grade leather needs thick coats of pigment to cover up cuts and scars.
  • Thickness - Leather thickness is measured in millimeters or ounces per square foot. One-ounce equals about 1/64-inch or 0.40 millimeters thickness. Jacket leather is usually between two and four-ounces.
  • Top grain - Leather from which only the hair and under flesh have been removed.
  • Grade - Leather grades range from A to D depending on the type and amount of flaws. Grade A hides are clean with no flaws. Grade B has a few slight imperfections. Grade C has healed cuts. Grade D has unhealed cuts. The higher the grade, the less pigment needed to finish the leather and the more beautiful the finished jacket.
  • Shearling - Sheepskin with the wool attached. The wool can be straightened or left naturally curly.
  • Mouton - Shearling tanned and finished for fur.

Leather Tanning Steps

  1. Raw skins are soaked in a vat of salt brine to temporarily preserve them.
  2. Preserved skins are soaked for several days in a solution of lime and sodium sulfate to remove hair and fat.
  3. Clean skins are treated in a bating vat with an enzyme and sulfate or chloride to remove the lime.
  4. Hides are placed in a tanning drum with chromium compounds or vegetable tannin.
  5. Tanned hides are placed in a fat liquoring drum with oils and greases to increase pliability.
  6. Hides are dyed with chemical or vegetable dyes in a rotating drum.
  7. Dyed hides are milled in a rotating drum to soften them.
  8. Milled leather is rolled, stretched, and dried to make it strong and uniform.
  9. Leather is finished with pigment, wax, oil or glaze.
  10. Finished leather may also be buffed or polished.
Gibson & Barnes
1900 Weld Blvd, #140
El Cajon, CA 92020

About This Page: Gibson & Barnes is America’s largest manufacturer of high-quality, made-to-order, flight suits, uniforms, leather jackets, and flying helmets for aviation, emergency medicine, and law enforcement.