The processing of hides and skins into leather is a fascinating procedure that requires a precise combination of many chemical and mechanical operations. Below you will find a cutting instructions for your leather, along with a step-by-step summary of these processing operations as provided by our suppliers.
CUTTING INSTRUCTIONS
A hide of genuine leather is nature's product and caution must be exercised in cutting one. The above diagram shows various areas of a hide and they are cut as follows:
Section A should be used in cutting seat tops, inside backs, cushion bands, and other sections that will receive the most strain and usage of flexing. Section A is the prime portion of the hide.
Section B should be used for outside arms, backs, hidden bands, or other parts of furniture that will receive little or no flexing. The flank sections must be used on outside backs and nonwearing surfaces in order to avoid trouble. Flank fibers run generally in one direction as indicated by the arrow. In applying flank sections to a chair, the first pull should be taken in the direction of the arrow. A stretch at right angles to the direction of the arrow may cause the finish to crack.

THE LEATHER PROCESS
Follow this step-by-step process to see how tanneries convert a natural resource into leather hides ...

 1 CURING
Deterioration begins immediately when a cow is killed. After the hides are removed from the carcass, they are salted through and through at the slaughterhouses to prevent decay. After they are salted, 55% of the water in the hide is removed, and they are dried for 3 to 6 days. The rawhides are then sold to tanneries.		 2 SOAKING
In order for the tanning process to work properly, the dry salted hides must be washed free of the salt. This is done by soaking the hides in water to which chemical wetting agents (similar to household detergents) and disinfectants are usually added for 8 to 20 hours, depending on the thickness of the hides. This soaking procedure rehydrates the hides to their original flaccid condition and removes the dirt.
3 DE-HAIRING
The hair must now be removed from the hides. This is done by soaking the hides in chemicals, or depilatory agents, which destroy the hair by attacking the hair root so it will release freely from the hides, loosen the epidermis, and remove certain soluble skin proteins that lie within the hide substance without destroying the desirable collagen of the hides.

4 FLESHING
Excess flesh, fat and muscle must now be removed from the hides. This is done with a fleshing machine.

 5 DE-LIMING
All the depilatory chemicals must now be removed from the hides. This is done by washing the hides in ammonium sulfate or ammonium chloride and then clear water in big drums. These chemicals not only clean the depilatory chemicals from the hides, they also adjust the acid-alkaline conditions (pH) to the proper point for receiving the bate-which are enzymes similar to those found in the digestive system of animals. When the bates are applied, they attack and destroy most of the remaining undesirable constituents of the hide.
6 PICKLING
The hides must be placed in an acid environment (low pH) so they will be ready to accept the tanning materials, because chrome tanning agents are not soluble under alkaline conditions. This is accomplished by adding salt and acid to the hides. This is a preserving process in itself, and hides can be kept in this state for extended periods of time without any deterioration.		 7 TANNING
The raw collagen fibers of the hides must be converted into a stable product which is no longer susceptible to rotting. This is done by adding chrome tanning agents to the hides in a revolving drum. These tanning agents also significantly improve the hide's dimensional stability, abrasion resistance, resistance to chemicals and to heat, the ability to flex innumerable times without breaking, and the ability to endure repeated cycles of wetting and drying.

8 WRINGING
The excess moisture must be removed from the hides. This is done by placing each hide through two large rollers similar to those on a clothes wringer.
9 SPLITTING
The hides must now be split into the desired thickness. Unsplit hides average to be 5mm thick. The thickness for upholstery leathers range from .9mm to 2.0mm. The hides are put through a splitting machine that is set to split the hides to the desired thickness. It cuts the top grain off first. Another layer, and sometimes two, are cut. These layers are called splits.		 10 SHAVING
The thickness of the hides must be made uniform all over the hide. This is done with a shaving machine through which the hides are run. The helical shaped cutting blades level the overall thickness to exact specifications and open the fiber structure to better receive subsequent chemical processing.		 11 RE-TANNING
This process is done to impart special end-use properties with other tanning chemicals. The substances used add solidity and body to chrome leather and help minimize variations in the character of the leather that may still exist between different parts of the hide.
12 COLORING
As soon as the retanning process is completed, aniline dyes, derived primarily from petroleum and added to very hot water, are added to rotating drums to penetrate the hides for desired color.		 13 FATLIQUORING
This is the last of the wet chemical operations to which the leather will be subjected. Fatliquoring has the most pronounced effect on how soft a leather will be and it contributes greatly to its tensile strength. The more fatliquors that are added, the softer the hides will be.		 14 SETTING OUT
This operation smoothes and stretches the hide, while compressing and squeezing out the excess moisture. This puts the hides in the proper condition for drying.

15 TOGGLING
The hides are stretched across a perforated frame and held in place with clips called toggles. One hide is clipped to each side of the frame. The frames are then slid into channels in drying ovens.

16 STAKING
Leather is staked to make it pliable. In combination with the correct fatliquoring treatment, staking governs the final firmness or softness of the leather.

17 DRY MILLING
The hides are placed in a large dry drum and tumbled until the desired softness is obtained.
18 BUFFING
This process improves the final appearance of the hides by lightly sanding the surface to remove some of the natural imperfections such as scratches, healed scars, etc. It provides the hide with better cutting yield.		 19 FINISHING
This process applies film-forming materials on the surface of the hide. Here is where layers of pigments are added if required. This process also adds the protective sealant to the surface.

20 PLATING (EMBOSSING)
This is the final step in the leather process. During this process, heat presses a chosen grain into the surface of the hides.

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