PURE ANILINE
Only the finest hides in the world fall in this category. Lovers of truly natural products are particular fond of these leathers. Through the years this type of leather develops a patina which adds to its value as a focal point in any room. Only 5% of the total » world hide supply fall in this category.-Only » A grade meet this criteria.
FULL ANILINE
Also, some of the finest hides in the world fall in this category. The only difference is a slightly lower selection of hides can be used here. A slight protective finish ( usually micropigments) is applied by roller or in the tannage to give the leather some » servicability
SEMI ANILINE / ANILINE PLUS
These leathers are processed a little more, first by aniline dying in large drums like the leathers above, but then also finished on top. Spray pigments of color are applied to the tops of the hides to even out the finish and camouflage natural occurring imperfections. These leathers are light resistant and scratch resistant and are easily cleaned. The next 10 - 15% of the world wide hide supply.» B grade hides meet this criteria.
CORRECTED GRAIN LEATHER
The next 18% of hides fall into this category of leather. These leathers have more processing done like sanding, buffing. embossing and heavily pigmenting, to cover natural imperfections. Insect bites, barbed wire scrapes, horn scratches, etc,are removed to a uniform thickness by sanding before finishing. Top grain leather is from the top 3/64 of an inch or .9 mm to 1.5 mm of the outer grain of the leather hide. See » properties of leather and is the minimum recommended for furniture, not splits as shown in the cuts below. » "C" grade hides meet this criteria. The last 65% of the world hide supply is not suitable for upholstery, instead it is used for clothing, shoes, belts,handbags, industrial, and the automotive industry.
TOP GRAIN LEATHER
The most confusing term used in the furniture industry is the term " top grain'. It can be a contradiction because it often implies what it is not. "Top grain", is the definition that is generally used when the grain is not genuine: when the real grain is sanded away and an imitation grain is stamped into the leather. When the genuine grain remains, the leather is called, "full grain," or " full top grain, " not simply" top grain."
Webster dictionary offers nearly a hundred definitions for the word "top". They include: the highest point,the summit, the best, the upper-surface, the lid, the supreme, the choicest part, the cream, the pick. It also means to excel, to surpass, to dominate or to be superior to the rest.
When one hears the term "top grain" it's reasonable to assume it's the best. But, if the real grain is gone, can that be true? If the real grain was removed and replaced by an imitation grain, the result is neither the best nor the uppermost.
If you want the best, insist upon leather which retains the entire original grain. Insist upon receiving the full grain.
Top grain is generally not the tops!
FULL GRAIN LEATHER
Just as the grain , texture and markings of wood should reveal the nature of the tree from which it came, leather should display the natural markings and grain characteristics of the animal from which it was taken. The best upholstery leathers are clear,clean, and supple. They are also dyed through with transparent aniline dyes. The full natural grain is retained and they are called "full grain leather."
Cheaper leather have the natural or genuine grain sanded away and an imitation grain pressed or embossed into the surface.They are stiff and "boardy" with a heavy coating of pigmentation to cover up imperfections and they look and feel much like plastic.
The better the quality of hide or skin, the less it has to be treated. The natural grain variations should be exposed. One should see the "fat wrinkles" and the feel, or hand, should be supple and natural to the touch. So when choosing your leather, make sure it looks natural, smells good, and has a soft hand. Inspect your leather carefully. Make certain that it retains the full natural grain.
Full grain leather - it is the tops!
Hides selected for furniture are sliced to a uniform thickness on precision machines. Only the surface (top grain) is used. The lower portions or splits are weaker, due to the elongated cell structure. Splits are subject to stretching and therefore provide an unstable base which results in cracking of topcoat finishes. The familiar "chamois" used in auto care is an example of split leather.
These terms below are classified at the tannery level and are not grades of leathers used by manufacturers. For furniture manufacture grades, see individual companies for their leather grading structure.
"This information listed here is a grading structure used at the tannery level and are not grades of leather used by manufacturers on their furniture.
For the production of every kind of hides for furnishings, from the most prized to the most ordinary, hides from various countries and regions are used. Pig hides are also used in the furniture industry, but this sort of leather does not meet durability requirements or quality. The place of origin of raw hides can be divide into three groups.
A. Hides from Southern Germany, Hides from Swiss pastures, Scandinavian Bull hides from Norway and Finland. Hides from Northern Italy.
B. Hides from Northern Germany, English hides, Dutch hides, and North American US hides.
C. Australian Hides, African hides, South American hides, Hides from Asia.
Raw Material
Today we think of leather as a commodity, something that is pretty much the same everywhere. Not true.Leather for furniture comes mostly from cattle and no two hides are alike. Age, heredity, and the environment all influence the character of leather. Leather is the strongest most versatile natural resource. It should be understood that cattle leather is a byproduct of the meat industry, and are raised for beef consumption. Leather is a renewable resource, so it allows us to create valuable products out of what otherwise would be waste. The largest sources of cattle hides are the beef herds of North and South America.
TANNING PROCESS
RAWHIDES
- Contain high amount (about 70%) of water and become hard and inflexible after drying.
- Can be easily attacked by bacteria and rot. They have to be kept refrigerated or the water removed by some means (not very useful for making into upholstery!)
- Are dirty with blood, dung, etc., sticking to it and contain hair and other materials which are not needed.
For making into upholstery, the leather should be
- Dry and flexible
- Stable
- Should have color, softness and other properties for the specific use.
Tannery operations achieve the above changes.
Tanning makes the leather fiber resistant to bacterial attack. Nowadays, chrome tanning is the most popular method. The modern leather processing can be divided into three parts:
- Preparation of wet blue (chrome tanned leather)
CHROME TANNING.
- Modification of the properties as needed in the final leather.
- Finishing on the surface.
Most of the processes in 1 and 2 are done inside drums (or other vessels) as batch operations in water (orange colored in the text) and a few operations are carried out in special machines on individual hides/skins
Preparation of wet blue (chrome tanned leather)
The first job in the tannery is to give the hides a good wash, with water, some special detergents and some other chemicals. This is called Soaking
Any loose flesh (remember, hides are taken from animals killed for meat!) sticking to the flesh side is scraped off by a knife (using a specially designed machine). This is called Fleshing.
Unhairing
removes the hair on the skin using certain chemicals, which can eat away the hair but not the hide fiber.
The chemicals used to tan the hides and modify the color, softness and other properties should be able to penetrate into the fiber network. The fiber network should be opened up and most other non-fibrous material removed. This is done in Liming. A process is used that requires a special soaking which uses alkali (lime) to increase the water entering the fiber network. Natural grease is also removed in this alkaline solution.
Normally, for the production of upholstery leathers the hides are split in to two layers in a machine using flat knife. The primary purpose of this operation is to make the thickness of the hide uniform throughout. Originally the hide is thickest in the neck portion of the animal and thinnest at the belly portion. The top layer, which is stronger and of uniform thickness, is used for making upholstery leather. The bottom layer is of non-uniform thickness and processed for different uses.
Then a series of adjustments in the acid/alkali balance (pH) of the hide is done before applying the chrome tanning salts. These operations are called Deliming and Pickling.
Chrome tanning salts penetrate the hide and react chemically with the molecules, making the fiber network resistant to bacteria. Modification of the properties as needed in the final leather product.
The main properties modified here are:
- Leather Thickness
- Color
- Softness
A number of other characters can be changed depending on the type of the leather being made by using specific chemicals.
Thickness is reduced by a Shaving machine, which shaves some thickness off from the back of the hide to make it more uniform in thickness.
After adjusting the pH balance, further chemical treatments are carried out.
Retanning uses special plant material or synthetic material to modify a range of properties. Dyes used in dyeing, color the fibers of the leather. Specially prepared oils are used in fatliquoring to make the leather soft (the oils lubricate the fibers). Special requirements such as water proofing, flame proofing, solvent resistance etc. can be fulfilled at this stage.
The leathers are stretched and flattened in Setting Machine and dried. After drying the leather is subjected to mechanical operations to make it soft, flat and tight. Either side can be modified by emery paper on a buffing machine.
FINISHING ON THE SURFACE.
A wide variety of finishing operations is carried out on the leather surface. The most common type is coating with colored mixes. Also worth mentioning is buffing the leather surface with emery (sandpaper) to get a suede or nubuck surface (velvet like surface) and an application of oils and waxes to get a pull up effect. You can see the different types of finishing done on upholstery leathers in the section on types of leathers.
Finishing modifies the surface color, gloss, and the final appearance of the leather. It also provides a protection to the surface from water, wear and abrasion.
Leather Types
ANILINE:CLEANING CODE A
also called NATURAL,PURE,NAKED,OR UNPROTECTED.
Ways to identify ANILINE:
For care and maintenance purposes check to see if the surface has been brushed (has a texture like velvet) or not. This is the point at which people have difficulty distinguishing NUBUCK from ANILINE. There are several ways you can identify an ANILINELeather:
- Lightly scratch the surface to see if it leaves a lighter color scratch mark. If it scratches to a lighter color, it is ANILINE. This is not the only test to do because some NUBUCKS will do this also.
- Wet your finger and lightly rub it into the Leather to see if it darkens. It should darken lightly, but dry invisibly.
"Pull-ups", are leathers that have a deep richness to them from fat liquors applied during the tanning process. These leathers have a unique characteristic, a "Pull-Up" effect when the leather is stretched it will tend to lighten up in that area but the color returns when heat is applied or friction from rubbing a cloth or your hand in that area. These leathers also tend to scratch easy but have an "Old World" effect or "Aged"look. Products recommended here included "Oleosa" and if the leather has a wax coat apply "Wax On" to replace this wax that is removed with fingernails from use.
PROTECTED:CLEANING CODE P
also called FINISHED,SEMI-ANILINE,EVERYDAY,PIGMENTED OR PAINTED.
Ways to identify SEMI-ANILINE (PROTECTED):
PROTECTEDLeathers are the most common Leathers, and for most consumers the most practical.
- Lightly scratch the surface to see if it leaves a lighter color scratch mark. If it does not scratch to a lighter color (this means the color remains the same), then this is a Protected Leather.
- Use SOFT CLEANER and clean the leather. The cleaner should stay on top of the finish and should not darken the Leather.
- The surface should have some sort of sheen to it. It is like looking at wood that has a lacquer finish compared to a wipe-on treatment.
NUBUCK:CLEANING CODE N
also called CHAPS,DISTRESSED,BOMBER OR SUEDE.
Ways to identify NUBUCK:
- The surface should have a texture similar to velvet. You move your hand across the surface and, if it leaves shading traces similar to the effect when you vacuum a carpet in one direction and then in another, it is Nubuck.
- Wet your finger and rub it lightly on the surface. The surface will darken and also will dry to a slightly darker shade.
The Language Of Leather
Full or Pure Aniline
- The finest leather available,always made from premium -quality, full-top grain hides(the suface of the hide has not been mechanically altered)
- The softest, most luxurious and natural looking leather
- More likely to fade and stain, will feature noticable range marks, barbed wire scars, wrinkles, scratches and brands.
- Unretouched, resulting in subtle color and shading differences from hide to hide and even within the same hide.
- Generally more expensive than other types of leather.
- Top 5% of world hide supply
Semi Aniline
- High quality. high value, always top grain
- Soft and beautiful;durable and practical
- Often coated with clear sealant to enhance stain resistance.
- Slightly more uniform in color and texture than full aniline.
- Fewer noticeable range marks because of top finishing.
- Generally less expensive than full aniline leather.
- Falls into top 10% of world hide supply.
Nubuck Leather
- High quality,top grain leather buffed or sanded to a velvety, sueded like nap.
- More likely to fade or stain, will feature noticable range marks and barbed wire scratches,wrinkles,healed scars,manure burns.
- Usual the softest of leathers, more durable than a true suede that is produced from the lower quality split of leather.
- Falls into top 10-15% of world hide supply
- Generally less expensive than Semi Aniline leather.
Pigmented Leather
- Least likely to fade or stain.
- Opaque dyes and pigments create uniform coloration that minimize natural marks and scars.
- Excellent durability with minimal maintenance.
- Falls into top 20-30% of world hide supply
- Generally less expensive than Nubuck leather.
Bonded Leather
- Least likely to fade or stain.
- Most economically priced.
- An artificial material composed of 10% to 20% leather fibers
- Excellent durability with minimal maintenance.
- Similiar to particle board or OSB board is to solid wood
- Description:↓
- Bonded leather, or reconstituted leather, is usually derived from waste scraps from leather tanneries It consists of collagen fibers obtained from macerated hide pieces bonded together with latex binders or fabric fillers constructed into a fibrous mat to create a look and feel similar or sometimes identical to that of genuine leather but at a fraction of the cost . Depending on the quality a man-made pattern is usually discernible as a "grain-like" look.
