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The
information provided below was taken from several books
and reports about leather. It is provided to help our
customers make a very good and informed purchase decision,
with confidence.
There is alot of misinformation in circulation,
some is due to misconceptions that are passed along
as facts and some is deliberate to mislead consumers.
Here we breakdown some basics about leather creation. |
Frequently asked questions about
leather and how it is made
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What
Is Leather? <Back
to Contents>
Leather tanning is the process of converting
raw hides or skins into leather. Hides and skins have
the ability to absorb tannic acid and other chemical
substances that prevent them from decaying, make them
resistant to wetting, and keep them supple and durable.
The surface of hides and skins contains
the hair and oil glands and is known as the grain side.
The flesh side of the hide or skin is much thicker and
softer. The three types of hides and skins most often
used in leather manufacture are from cattle (cows),
sheep and pigs.
Timot uses only
high quality YKK zippers in its products -- the quality,
reliability, and wear are unbeatable. Read
more about what makes a zipper special ...
Real leather is composed of many microscopic
fibers which are inter-linked. When leather is used,
it bends and the fibers bend and rub against each other.
When it was alive and connected to the oil ducts of
the animal, the fibers were all naturally lubricated.
During tanning, the oils are first extracted, then
later replaced with other oils (usually called "fat
liquors.") Once the leather has been tanned, these
oils will eventually dissipate (faster in hot weather
and exposed to the sun). At this point oils must be
reapplied to the leather or the fibers will start
cutting into each other as the leather bends and flexes;
cut fibers result in cracks in the leather.
Once leather develops cracks, the cracks
cannot be repaired, although further cracking can be
prevented by applying oil or conditioners to the leather.
Silicone waterproofing is only a surface coat and will
not properly lubricate the leather fibers. Silicone
can prevent oils from entering and lubricating leather
so is only a quick fix for water-proofing.
Using a natural
oil is very good although it will darken most leathers.
A general purpose leather lotion or even hand lotion
will replenish fiber lubrication and some will not
darken the leather except temporarily.
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Why Use Cowhide? <Back
to Contents>
Cowhide is the most common leather used
in the making of garments, furniture and leather goods.
Cowhide as a category covers a wide spectrum of textures
and quality, but generally, it is quite durable, easy
to care for and resistant to water and dirt.
Cowhide leather
will maintain its integrity, taking on the shape of
the wearer, making it more comfortable with everyday
use. This affordable, functional leather offers fashion,
value and endless colors and style.
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The best leather is full grain
leather. The reason it is best is because it
is the strongest part of the leather. At the top of
the skin, or epidermis level, fibers are tighter together
and hence stronger. In order to be considered "full
grain leather" the leather cannot have been buffed or
sanded on the top.
Therefore, at the surface the leather
fibers are most closely inter linked, and hence strongest.
When any of these fibers are buffed (sanded) in order
to reduce the number of apparent blemishes, leather's
natural strength diminishes.
Timot uses full grain leather for making
all of its leather goods. We do not
use Milled Leather. Milled leather is NOT
strong enough for motorcycle apparel because the surface
has been buffed, sanded and the grain pattern has been
stamped into the leather, i.e. pig leather with a cow
grain pattern stamped onto it. It is not strong because
the upper most level of the epidermis has been removed
and it is not necessarily cowhide.
Only the best (least
damaged) skins can be used for making full grain leather.
The more natural the dye and top coatings, the more
transparent they are. These transparent dyes are usually
aniline. Only a small percentage of skins can be used
to produce an aniline dyed full grain leather.
Full grain leather may be hot plated or
not, the plating (done with a large metal plate which
has usually been etched to look like a perfect full
grain leather) being added to hide some of the natural
defects in leather. |
What Are Good Properties of Leather? <Back
to Contents>
The properties of leather vary considerably
depending upon the type and quality of both the skins
and tanning process. Every piece of leather has individual
markings which relate to its origins and add character
to each skin.
Like a fine wine,
a good quality leather garment should improve with
age. The natural elasticity of each hide means it
is flexible and will stretch and return to its original
shape. Leather also has a natural tendency to repel
liquids and resist staining. It's also fire resistant,
and emits no toxic fumes, even when exposed to intense
heat.
Relative to virtually all man-made textiles,
leather is very strong and has a high resistance level
to tears and punctures. The comfort provided by most
leather goods is due in part to leather's ability to
combine breathing and insulating properties. You may
have heard... "Leather is hot in summer and cold in
winter." In reality, leather adjusts constantly to its
environment. Because it is a natural product, leather
"breathes" freely, maintaining a comfort level in all
seasons. |
What Is the Difference Between Top Grain and Full Grain
Leather? <Back
to Contents>
Top grain leather is full grain leather that has usually
been buffed and has originated from the top of the skin.
However, not all top grain leather is full grain leather.
Most top grain leather will be buffed then hot stamped
with an enormous metal plate.
The finest leathers
do not need to be plated, but are rare in a world
of bugs, barbs, bumps, bruises and brands. It is expensive
to raise animals in an environment that reduces the
possibilities for injuries. Not many farms that raise
cattle provide a flat plain with insect control, barbless
fences, and soft foliage due to the high cost.
The buffing process involves sanding off
the surface blemishes. Therefore, in this process the
leather is weakened because most of the tightest leather
fibers are removed.
The cheapest grades of "genuine leather"
usually use the cheapest hides (such as pigskin) to
replicate cowhide (it can still legally be called "genuine
leather.") The best tanneries produce excellent top
grain leathers because they only lightly snuff the leather
and use top quality finishes and processes to duplicate
the look of full grain leather. Often a smooth metal
plate or hair cell metal plate is applied with heat
and pressure to "kiss plate" the leather, or iron out
wrinkles and some irregularities and provide a higher
yield of cutting. |
What
Dye Process Does Timot Use?<Back
to Contents>
We use an Aniline and Semi-Aniline Leather
Dye Processes so that the color cannot be scratched
to reveal a natural color beneath the surface. If we
only pigmented the surface as is true with many leather
products, even the smallest of scratches would show
very easily.
Aniline Leather is tumbled in vats so
the dye is completely absorbed by the skin. There is
no other coloring agents or process, thus the finished
leather tends to look and feel more "natural" - the
unique markings and character of each skin are apparent.
By way of analogy, this treatment is akin to the "staining"
of wood.
Usually, the best
quality hides are reserved for this process, as aniline
leathers are valued highest by consumers.
Semi-Aniline Leathers which are a combination
of both pigmented and aniline dyed; a very light pigment
is added to even out the co lour and increase the durability.
Most garments are made with semi-aniline leathers. |
What Are Splits? <Back
to Contents>
Some hides are sliced to a uniform thickness
on precision machines.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 the finishes. These are not fit for use where strength
and durability are necessary. |
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Corrected Grain Leather
is leather whose natural surface texture has been
altered.
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Milled Leather is leather
that has been sanded, buffed and had a grain pattern
stamped onto it, i.e. "pig skin with a cowhide
pattern", it is therefore not good for motorcycle
apparel because the upper most level of the epidermis
(skin) has been removed and it is not necessarily
cowhide.
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Drum-dyed is a dyeing process
in which leather is immersed in dye and tumbled
in a rotating drum, allowing maximum dye penetration.
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Premium select is a term
describing hides with a minimal amount of scars
or blemishes, usually less than 5% of all hides.
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Semi-Aniline Leathers which
are a combination of both pigmented and aniline
dyed; a very light pigment is added to even out
the co lour and increase the durability. Most
garments are made with semi-aniline leathers.
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References
1) K. Bienkiewicz, Physical Chemistry Of Leathermaking,
Krieger Publishing Co., Malabar FL, 1983.
2) Leather Tanning, United States Department
of Agriculture - Food and Agricultural Industry Chapter
9, Section 15, June 1997.
3) Terry Scheller, Leather Quality Information,
www.atalante.com/leather.html, 2003.
4) All About Leather, www.carolinaleatherworks.com/allableat.html,
March 8, 2004.
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