All About Leather
Alex Matthews
For those of you that have a fascination with leather goods, I
am here to shed some insight of this wonderful material. Leather
is a material created through the tanning of hides, pelts and
skins of animals, primarily cows. Leather is a very important
clothing material, and its other uses are legion. Together with
wood, leather formed the basis of much ancient technology.
Leather with the fur still attached is simply called fur. There
are a number of processes whereby the skin of a dead animal can
be formed into a supple, strong material commonly called
leather. Vegetable-tanned leather is tanned using tannin (hence
the name "tanning") and other ingredients found in vegetable
matter, tree bark, and other such sources. It is supple and
brown in color, with the exact shade depending on the mix of
chemicals and the color of the flesh. Vegetable-tanned leather
is not stable in water; it tends to discolor, and if left to
soak and then dry it will shrink and become less supple and
harder. In hot water, it will shrink drastically and plasticize,
becoming rigid and eventually becoming brittle. Alum-tanned
leather is tanned using aluminum salts mixed with a variety of
binders and protein sources, such as flour, egg yolk, etc.
Purists argue that alum-tanned leather is technically "tawed"
and not tanned, as the resulting material will rot in water.
Very light shades of leather are possible using this process,
but the resulting material is not as supple as vegetable-tanned
leather. Rawhide is made by scraping the skin thin, soaking it
in lime, and then stretching it while it dries. Like
alum-tanning, rawhide is not technically "leather", but is
usually lumped in with the other forms. Rawhide is stiffer and
more brittle than other forms of leather, and is primarily found
in uses such as drum heads where it does not need to flex
significantly; it is also cut up into cords for use in lacing or
stitching, or for making dog toys. Boiled leather is a hide
product (vegetable-tanned leather) that has been hardened by
being immersed in hot water, or in boiled wax or similar
substances. Historically, it was used as armour due to its
hardness and light weight, but it has also been used for book
binding. Chrome-tanned leather, invented in 1858, is tanned
using chromium sulfate and other salts of chromium. It is more
supple and pliable than vegetable-tanned leather, and does not
discolor or lose shape as drastically in water as
vegetable-tanned. More esoteric colors are possible using chrome
tanning. Brain-tanned leathers are exceptionaly absorbent of
water. They are made by a labor-intensive process which uses
emulsified oils (often those of animal brains) and which has not
been industralized. They are known for their exceptional
softness and their ability to be washed. Leather--usually
vegetable-tanned leather--can be oiled to improve its water
resistance. This supplements the natural oils remaining in the
leather itself, which can be washed out through repeated
exposure to water. Frequent oiling of leather, with mink oil,
neatsfoot oil or a similar material, keeps it supple and
improves its lifespan dramatically. In general, leather is sold
in three forms... Full-Grain leather, made from the finest raw
material, are clean natural hides which have not been sanded to
remove imperfections. Only the hair has been removed. The grain
remains in its natural state which will allow the best fiber
strength, resulting in greater durability. The natural grain
also has natural breathability, resulting in greater comfort.
The natural Full-Grain surface will wear better than other
leather. Rather than wearing out, it will develop a natural
"Patina" and grow more beautiful over time. The finest
furniture, and footwear, are made from Full Grain leather.
Corrected-Grain Leather (also called "top-grain leather").
Corrected Leather is fuzzy on one side and smooth on the other.
The smooth side is the side where the hair and natural grain
used to be. The hides, which are made from inferior quality raw
materials, have all of the natural grain sanded off, and an
artificial grain applied. Top grain leather generally must be
heavily painted to cover up the sanding and stamping process.
Suede is an interior split of the hide. It is "fuzzy" on both
sides. Suede is less durable than top-grain. Suede is cheaper
because many pieces of suede can be split from a single
thickness of hide, whereas only one piece of top-grain can be
made. However, as the look of full-grain is in demand,
manufacturers use a variety of techniques to make suede appear
to be full-grain. For example, in one process, glue is mixed
with one side of the suede, which is then pressed through
rollers; these flatten and even out one side of the material,
giving it the smooth appearance of full-grain. Latigo is one of
the trade names for this product. Leather from other animals
Today, most leather is made of cow hides, but many exceptions
exist. Lamb and deer skin are used for soft leather in more
expensive apparels. Kangaroo leather is used to make items which
need to be strong but flexible, such as motorcycle gloves.
Kangaroo leather is favored by motorcyclists specifically
because of its lighter weight and higher abrasion resistance as
compared to cowhide. Leather made from more exotic skins has at
different times in history been considered very beautiful. For
this reason certain snakes and crocodiles have been hunted to
near extinction. In the 1970s, farming of ostriches for their
feathers became popular. As a side product, ostrich leather
became available and is currently used by all the big fashion
houses like Hermès, Prada, Gucci, and Louis Vuitton. Ostrich
leather has a characteristic "goose bump" look because of the
large follicles from which the feathers grew. In Thailand, sting
ray leather is used in wallets and belts in the same way as
regular cow leather. Sting ray leather is as tough and durable
as hard plastic. The leather is often dyed black and covered
with tiny round bumps in the natural pattern of the back ridge
of an animal. These bumps are then usually dyed white to
highlight the decoration. Preservation and Conditioning of
Leather The natural fibers of leather will break down with the
passage of time. Acidic leathers are particularly vulnerable to
red rot, which causes powdering of the surface and a change in
consistency. Damage from red rot is aggravated by high
temperatures and relative humidities, and is irreversible.
Exposure to long periods of low relative humidities (below 40%)
can cause leather to become desiccated, irreversably changing
the fibrous structure of the leather. Various treatments are
available such as conditioners, but these are not recommended by
conservators since they impregnate the structure of the leather
artifact with active chemicals, are sticky, and attract stains.
About the author:
Alex Matthews is a leather industry veteran involved in leather
goods manufacturing for the last 15 years. To get additional
information about the properties of leather please contact Alex
at info@emiliooneto.com or http://www.emiliooneto.com/ For more
information about leather products please visit
http://www.emiliooneto.com to realize the benefits leather
material
For those of you that have a fascination with leather goods, I
am here to shed some insight of this wonderful material. Leather
is a material created through the tanning of hides, pelts and
skins of animals, primarily cows. Leather is a very important
clothing material, and its other uses are legion. Together with
wood, leather formed the basis of much ancient technology.
Leather with the fur still attached is simply called fur. There
are a number of processes whereby the skin of a dead animal can
be formed into a supple, strong material commonly called
leather. Vegetable-tanned leather is tanned using tannin (hence
the name "tanning") and other ingredients found in vegetable
matter, tree bark, and other such sources. It is supple and
brown in color, with the exact shade depending on the mix of
chemicals and the color of the flesh. Vegetable-tanned leather
is not stable in water; it tends to discolor, and if left to
soak and then dry it will shrink and become less supple and
harder. In hot water, it will shrink drastically and plasticize,
becoming rigid and eventually becoming brittle. Alum-tanned
leather is tanned using aluminum salts mixed with a variety of
binders and protein sources, such as flour, egg yolk, etc.
Purists argue that alum-tanned leather is technically "tawed"
and not tanned, as the resulting material will rot in water.
Very light shades of leather are possible using this process,
but the resulting material is not as supple as vegetable-tanned
leather. Rawhide is made by scraping the skin thin, soaking it
in lime, and then stretching it while it dries. Like
alum-tanning, rawhide is not technically "leather", but is
usually lumped in with the other forms. Rawhide is stiffer and
more brittle than other forms of leather, and is primarily found
in uses such as drum heads where it does not need to flex
significantly; it is also cut up into cords for use in lacing or
stitching, or for making dog toys. Boiled leather is a hide
product (vegetable-tanned leather) that has been hardened by
being immersed in hot water, or in boiled wax or similar
substances. Historically, it was used as armour due to its
hardness and light weight, but it has also been used for book
binding. Chrome-tanned leather, invented in 1858, is tanned
using chromium sulfate and other salts of chromium. It is more
supple and pliable than vegetable-tanned leather, and does not
discolor or lose shape as drastically in water as
vegetable-tanned. More esoteric colors are possible using chrome
tanning. Brain-tanned leathers are exceptionaly absorbent of
water. They are made by a labor-intensive process which uses
emulsified oils (often those of animal brains) and which has not
been industralized. They are known for their exceptional
softness and their ability to be washed. Leather--usually
vegetable-tanned leather--can be oiled to improve its water
resistance. This supplements the natural oils remaining in the
leather itself, which can be washed out through repeated
exposure to water. Frequent oiling of leather, with mink oil,
neatsfoot oil or a similar material, keeps it supple and
improves its lifespan dramatically. In general, leather is sold
in three forms... Full-Grain leather, made from the finest raw
material, are clean natural hides which have not been sanded to
remove imperfections. Only the hair has been removed. The grain
remains in its natural state which will allow the best fiber
strength, resulting in greater durability. The natural grain
also has natural breathability, resulting in greater comfort.
The natural Full-Grain surface will wear better than other
leather. Rather than wearing out, it will develop a natural
"Patina" and grow more beautiful over time. The finest
furniture, and footwear, are made from Full Grain leather.
Corrected-Grain Leather (also called "top-grain leather").
Corrected Leather is fuzzy on one side and smooth on the other.
The smooth side is the side where the hair and natural grain
used to be. The hides, which are made from inferior quality raw
materials, have all of the natural grain sanded off, and an
artificial grain applied. Top grain leather generally must be
heavily painted to cover up the sanding and stamping process.
Suede is an interior split of the hide. It is "fuzzy" on both
sides. Suede is less durable than top-grain. Suede is cheaper
because many pieces of suede can be split from a single
thickness of hide, whereas only one piece of top-grain can be
made. However, as the look of full-grain is in demand,
manufacturers use a variety of techniques to make suede appear
to be full-grain. For example, in one process, glue is mixed
with one side of the suede, which is then pressed through
rollers; these flatten and even out one side of the material,
giving it the smooth appearance of full-grain. Latigo is one of
the trade names for this product. Leather from other animals
Today, most leather is made of cow hides, but many exceptions
exist. Lamb and deer skin are used for soft leather in more
expensive apparels. Kangaroo leather is used to make items which
need to be strong but flexible, such as motorcycle gloves.
Kangaroo leather is favored by motorcyclists specifically
because of its lighter weight and higher abrasion resistance as
compared to cowhide. Leather made from more exotic skins has at
different times in history been considered very beautiful. For
this reason certain snakes and crocodiles have been hunted to
near extinction. In the 1970s, farming of ostriches for their
feathers became popular. As a side product, ostrich leather
became available and is currently used by all the big fashion
houses like Hermès, Prada, Gucci, and Louis Vuitton. Ostrich
leather has a characteristic "goose bump" look because of the
large follicles from which the feathers grew. In Thailand, sting
ray leather is used in wallets and belts in the same way as
regular cow leather. Sting ray leather is as tough and durable
as hard plastic. The leather is often dyed black and covered
with tiny round bumps in the natural pattern of the back ridge
of an animal. These bumps are then usually dyed white to
highlight the decoration. Preservation and Conditioning of
Leather The natural fibers of leather will break down with the
passage of time. Acidic leathers are particularly vulnerable to
red rot, which causes powdering of the surface and a change in
consistency. Damage from red rot is aggravated by high
temperatures and relative humidities, and is irreversible.
Exposure to long periods of low relative humidities (below 40%)
can cause leather to become desiccated, irreversably changing
the fibrous structure of the leather. Various treatments are
available such as conditioners, but these are not recommended by
conservators since they impregnate the structure of the leather
artifact with active chemicals, are sticky, and attract stains.
About the author:
Alex Matthews is a leather industry veteran involved in leather
goods manufacturing for the last 15 years. To get additional
information about the properties of leather please contact Alex
at info@emiliooneto.com or http://www.emiliooneto.com/ For more
information about leather products please visit
http://www.emiliooneto.com to realize the benefits leather
material
posted by The Editor at
5:57 AM
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