-is a processed animal skin, mostly that of cattle.
It is
expensive for several reasons: such processing is labor
intensive, aniline dyes are costly, and there is a high
rejection rate of the finished hides.
1. Cattle Hide- the skin of a fully grown cow. Such skins
are large hides, ranging from 4.6 sq. m to 5.5 sq. m
(50 sq ft to 60 sq ft) The center portion of the hide,
called bend, yields the best quality hide.
2. Calfskin- is the hide of a young animal and is
considerably smaller, about 2.3 sq m to 3.2 sq m (25
sq ft to 35 sq ft). Calfskin is characterized by its
softness, suppleness, and fine grain.
- Defined by the surface imperfections and how it is processed.
1. Full-grain leather- sometimes call full-top-grain leather, it
possesses the genuine original grain of the hide. The surface
has not been sanded, buffed, snuffed, embossed or altered in
any way; it is the full, natural hide. The original grain remains
allowing the fiber strength and durability. It also has
breathability, resulting in les moisture from prolonged contact.
Full-grain leathers have the least amount of surface
imperfections. These constitute the most expensive type of
hides.
2. Top-grain Leather- this is the second-highest
quality, where the “split” layer is separated away,
making it thinner and more pliable than full-grain.
The original surface pattern, including scars from
barbed wire or brands, is removed by abrasion. A
finish coat added to the surface which results in a
colder, plastic feel, with less breathability
3. Corrected-grain Leather- any leather that had
artificial grain applied to its surface. The
imperfections are sanded off, and an artificial
grain is the impressed into the surface and
dressed with stain and dyes, since the solid
pigments help to hide the corrections or
imperfections
4. Split leathers- this is created from the fibrous
part of the hide that is left, once the top-grain has
been separated. The inside layer is often finished
as suede, but some split leathers have an artificial
layer applied to the surface and embossed with a
leather grain. Inexpensive leathers may be
pigmented split leathers with an embossed
imitation grain.
a. Buckskin or brained
leather- refers to the
leather that has undergone
a type of tanning process
that uses animal brains or
other fatty materials to alter
it. The resulting supple,
sued-like hide, is usually
smoke to prevent it from
rotting.
b. Patent Leather-
is a type of leather that
has been given a high
gloss finish. It is usually
black and is coated
with lacquer on the
final finishing process
to give it its
characteristic
glossiness.
c. Shagreen- also
known as stingray
skin/ leather. Used in
furniture production
since the art deco
periods. The term
originates from
France.
d. Slink- this is from the skin
of unborn calves. It is particularly
soft and is highly valued.
a. Bonded leather- also known as
‘reconstituted leather’, is composed of 90% to
100% leather fibers, bonded together with latex
binders to create a look and feel similar to that of
leather but only a fraction of the cost. This is not
as durable as the other leathers, and
recommended for use only if the product will be
used infrequently.
b. Bycast Leather-
a split leather with a
layer of polyurethane
applied to the surface,
and then embossed.
Originally made for the
shoe industry, it was
recently adopted by
the furniture industry.
1. Tanning- used to preserve the hide. It puts the life
back into a leather hide by replacing the natural
gelatinous materials found in the skin with tanning
solutions. Tanning makes the leather strong, supple,
and enduring. There are three primary tanning agents:
mineral, vegetable, and a combination of the two.
a. Mineral Tanning- the tanning solution
is based on chromium salts. Mineral tanned
hides accept dyes well, including rich, vibrant
colors. This makes for a leather that is more
subtle and pliable than vegetable-tanned
ones, and does not discolor or lose shape as
drastically in water. About 90% of leather
today is tanned by this method.
b. Vegetable tanning- tree bark, typically
oak, and water form the basis of this tanning
solution. The hides are submerged in the
solution, and tannins (tanning materials) from
the bark swell the hides. Vegetable tanned hides
have a heavier feel and a distinct smell. They are
often left undyed. This is not stable water since
it tends to discolor, and if left to soak and then
dry it will shrink and become less supple, and
harder.
c. Combination tanning- this
tanning method produces a hide
that is quite supple, with a limited
acceptance of dyes.
2. Finishing- finishes can color the leather and help to protect
it from hard wear. Dyeing, embossing, and acceptance of dyes.
Comparable to stains for wood that do not contain opaque
pigments, aniline dyes are translucent. They do not obscure
the natural grain pattern and surface imperfections. The best-
quality upholstery leathers are aniline dyed. The dye
penetrates through the depth of the hide completely so that
as the leather wears, the color remains the same. Semi-aniline
dyes contains some pigments. The normal variation from one
dyed hide to another can be quite noticeable. The use of semi-
aniline dyes helps to ensure uniformity in color among many
hides.
