Ivory

See also Ivory carving.. These non-machine knitting tools have been called many different names, including knitting looms or knitting frames,which can lead to confusion with knitting machines. So-called hornbill ivory, derived from a bird, is not true ivory but resembles it in some ways. Stitches are formed by lifting loops over a peg or nail, one stitch at a time, to produce flat or more often tubular fabric. [1]. Knitting can be performed on other tools which have no moving parts, for example e knitting nancy and larger tools of that family. It is sometimes called vegetable ivory, or tagua, and is the seed endosperm of the ivory nut palm commonly found in coastal rainforests of Ecuador and Peru. The Standard 200 bed knitter can knit the finest yarns up to a good sportweight while the heavier yarns knit better on a bulky knitting machine.

A species of hard nut is gaining popularity as a replacement for ivory, although its size limits its usability. garter stitch) are much easier to produce with handknitting. Mammoth ivory is used today to make handcrafted knives and similar implements. Some stitch patterns (e.g., tuck stitches) are much easier to produce with a knitting machine, while others (e.g. Trade in the ivory from the tusks of dead mammoths has occurred for 300 years and continues to be legal. Many people prefer the look of hand knitting and skilled hand knitters can produce quite even fabric, while machine knitters need little skill to produce a good fabric as the machine tension does the job for them. Kenya, which saw its elephant populations plummet in the decade preceding the 1989 ban, claims that legalizing ivory trade anywhere in Africa will endanger elephants everywhere in Africa as poachers would attempt to launder their illegal ivory with legal stockpiles. This is an advantage, and saves a considerable amount of time.

Yet, a 1999 study done by Oxford University found that less than one percent of the five-hundred million US dollars ivory sales generate ever reach Africans; most of it goes to middlemen and vendors, so the effectiveness of the policy is in question. The fabric produced using a knitting machine is of a more even texture than hand-knitted fabric, which is particularly noticeable on large areas of plain stocking stitch. In 2002 the United Nations partially lifted the ban on ivory trade, allowing a few countries to export certain amounts of ivory. Knitting machines work an entire row of loops in a single movement. Many African countries including Zimbabwe and South Africa claim that ivory trade is necessary—both to stimulate their economies and reduce elephant populations which are allegedly harming the environment. Knitting proceeds more quickly than in hand knitting, where (usually two) straight needles are held in the hand and each stitch is manipulated individually across the row. Since the worldwide ivory trade ban in 1989 there have been ups and downs in elephant populations, and ivory trade as bans have been placed and lifted. Domestic knitting machines use the weft knitting method which produces a fabric similar to hand knitting.

Much of the decline in population is due to poachers during and before the 1980s. The yarn passes through a tensioning mechanism and down through the knit carriage, which feeds the yarn to the needles as they knit. Due to the rapid decline in the populations of the animals that produce it, the importation and sale of ivory in many countries is banned or severely restricted. With the addition of a lace carriage, stitches can be transferred from one needle to the next. Additionally, warthog tusks, and teeth from sperm whales, orcas and hippos can also be scrimshawed or superficially carved, thus retaining their morphologically recognizable shapes. With knitwoven fabric, the purl side (usually the wrong side) is the right side of the fabric. A small example of modern carved ivory objects are small statuary, netsukes, jewelry, flatware handles, furniture inlays, and piano keys. Knitweaving refers to a technique in which a separate piece of yarn, often heavier than the knitted fabric, is carried along and caught between stitches to produce an effect like weaving.

Tooth and tusk ivory can be carved into an almost infinite variety of shapes and objects. Plated effects can be particularly striking in a ribbed fabric. The North African elephant population was probably reduced to extinction, due to the demand for ivory in the Classical world. Plating refers to knitting with two strands of yarn that are held in such a way that one is in front of the other. Ivory was often used to form the whites of the eyes of statues. Most of these machines can knit two colour "fair isle" patterns automatically, and have machine stitch patterning features such as plating and knitweaving. Both the Greek and Roman civilizations used large quantities of ivory to make high value works of art, precious religious objects, and decorative boxes for costly objects. Needles can be placed in holding position to allow short row shaping.

Paleolithic Cro-Magnon man, during the late stages of the ice age, were the first to carve in ivory (mammoth tusks). Thus needles will knit or not, and the unknitted yarn portions will lie under (slip stitch) or over the needle or be held in the needle hook (tuck stitch). The three dimensional configuration of the dentinal tubules is under genetic control and is therefore a characteristic unique to the order. punch cards, particular needles can be caused to travel by alternate pathways through the cam box. Their length is dictated by the radius of the tusk. By various selection methods, e.g. These canals have different configurations in different ivories and their diameter ranges between 0.8 and 2.2 micrometres. A carriage or cam box is passed across the bed of needles causing the needle movements required to produce each next stitch.

Dentine contains a microscopic structure called dentinal tubules which are micro-canals that radiate outward through the dentine from the pulp cavity to the exterior cementum border. Late 20th Century domestic/studio/home models typically use up to 200 latch hook needles to hold the stitches in a standard or bulky size needle. The inorganic component of dentine consists of dahllite. Ribbing attachments can be added to single bed machines to achieve a similar result. Dentine is a mineralized connective tissue with an organic matrix of collagenous proteins. Double bed machines have two flat beds facing each other, in order to produce purl and plain rib fabrics plus a variety of multi patterns. Dentine, which is the main component of carved ivory objects, forms a layer of consistent thickness around the pulp cavity and comprises the bulk of the tooth and tusk. There are domestic and industrial models, with either flat or circular beds that produce rectangular or tubular fabrics.

Odontoblasts line the pulp cavity and are responsible for the production of dentine. Pattern stitches can be selected by hand manipulation of the needles, or with push-buttons and dials, mechanical punch cards, or electronic pattern reading devices and computers. The pulp cavity is an empty space within the tooth that conforms to the shape of the pulp. Knitting machines can be hand powered or motor assisted. The innermost area is the pulp cavity. The knitting machine, sometimes called knitting frame, knitting loom, or hand knitting machine, is used to produce knit fabrics on a fixed bed of hooked needles. Teeth and tusks have the same physical structures: pulp cavity, dentine, cementum and enamel.

The teeth of most mammals consists of a root and the tusk proper. Tusks, which are extremely large teeth projecting beyond the lips, have evolved from teeth and give certain species an evolutionary advantage. Teeth are specialized structures adapted for food mastication. Teeth and tusks have the same origins.

Therefore, "ivory" can correctly be used to describe any mammalian teeth or tusks of commercial interest which is large enough to be carved or scrimshawed. The chemical structure of the teeth and tusks of mammals is the same regardless of the species of origin, and the trade in certain teeth and tusks other than elephant is well established and widespread. . Plastics have been viewed by piano purists as an inferior ivory substitute on piano keys, although other recently developed materials more closely resemble the feel of real ivory.

The word "ivory" was traditionally applied to the tusks of elephants. Prior to the introduction of plastics, it was used for billiard balls, piano keys, buttons and ornamental items. Ivory is a hard, white, opaque substance that is the bulk of the teeth and tusks of animals such as the elephant, hippopotamus, walrus, mammoth, etc. Elk Ivory from the bugling teeth of bull elk.

Warthog ivory. Hippopotamus ivory. Narwhal ivory. Sperm Whale and Killer Whale ivory.

Walrus ivory from the tusks of a bull walrus. Elephant and mammoth ivory from the tusks of bull elephants and mammoths.