Warp, in woven carpet, refers to yarns running lengthwise.
The easiest way to remember that warp is associated with length is
to think of “warp” speed as in Star Trek®. Weft, in
woven carpet, refers to yarns running widthwise between warp
yarns. The easiest way to remember that weft is associated with
width is to think “weft” and "right”.
There
are two major rug-weaving techniques: pile (or knotted) weave and
flat weave.
Pile
weave or knotted weave is the method of weaving used in most rugs.
In this technique the rug is woven by creation of knots. A short
piece of yarn is tied by hand around two neighboring warp strands
creating a knot on the surface of the rug. After each row of knots
is created, one or more strands of weft are passed through a
complete set of warp strands. Then the knots and the weft strands
are beaten with a comb securing the knots in place. A rug can
consist of 25 to over 1,000 knots per square inch.
Flat
weave refers to a technique of weaving where no knots are used in
the weave. The warp strands are used as the foundation and the
weft stands are used as both part of the foundation and in
creating the patterns. The weft strands are simply passed through
the warp strands. Some examples of this weaving method can be seen
in kilims, soumaks and brocades. These weavings are called flat
weaves since no knots are used in the weaving process and their
surface looks flat.
Kilims are the best-known group of flat-woven rugs. Because they
take less time to weave, they are generally less expensive than
(knotted) rugs. The main difference between kilims and pile rugs
is that in kilims the weft strands create the colorful patterns.
No rows of knots are added. The weft strands, unlike a pile rug,
are discontinuous. They do not pass through the warp strands from
selvage to selvage (edge to edge). The weft strands are passed
through a few warp strands; then, they loop back around when they
reach a section where a new color weft is needed.
The
Soumak weaving technique refers to a method of flat weaving where
the wefts are passed over two or four warps and back under one or
two warps.
Brocade
is also a form of flat weaving. Brocades already have a foundation
(a warp and a weft). The foundation is patterned by additional
colored weft strands, which can be continuous or discontinuous,
and are passed through the already existing warp and weft strands.
The
three most important weaving methods for carpet are Axminster,
velvet, and Wilton.
In
Axminster, the loom has control over each tuft of
yarn making up the carpet. Axminster carpets are usually
complicated designs and are always cut-pile. Spools of yarn that
feed the loom can hold different colors and even different kinds
of yarn.
In
the Velvet loom, the pile yarn loops are formed
over “wires”, one wire for each row of tufts. The wires are then
pulled out, leaving a row of tufts. A knife blade, similar to a
razor blade, may be attached to the end of the wire. As the wire
is extracted, the tuft is cut to form a cut pile carpet. If no
blade is attached, the carpet remains a loop pile.
The
Wilton loom uses a mechanism to regulate the
feeding of pile yarns into the loom to form a pattern. Joseph
Marie Jacquard invented this in 1801. Sculptured carpets are made
by controlling pile height and cutting, or not cutting
loops.
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