Natural Plastics

//Natural Plastics
Natural Plastics 2015-07-16T08:00:42+00:00

Natural Plastics

Horn

Horn has been referred to as a natural plastic and is similar to modern thermoplastics in that it tends to revert to its original shape. Despite the simple processes that remain unchanged in working horn, the horner’s experience and judgement are critical in overcoming this tendency to revert to its original shape. The colours of horn range from ebony to shades of cream and when subjected to heat and pressure it can become translucent.

The use of horn was universal wherever there were herds of cattle, goats and flocks of sheep and certain antelopes. Despite being a unique and extremely versatile resource horn is almost forgotten as a raw material. Its use since ancient times for drinking horns, containers and sounding horns is well documented. It was also used for many items essential to daily life such as combs, spoons, knife and tool handles, horn cups and objects of great beauty. In some cases horn objects had a symbolic significance.

Unless horn has been buried in a waterlogged site (where oxygen has been excluded) it decomposes. Much evidence has been lost but certain words such as lanthorn, inkhorn, horn-rimmed spectacles and powder horn indicate the wide use of horn in the past. The craft has been in decline since the early years of the twentieth century because many objects made in horn are now produced more cheaply in modern thermoplastics.

In 1943, the Worshipful Company of Horners formed a close association with the Plastics Industry who are the logical successors to this ancient craft. The Horners’ Company was first recorded in 1284 in the City of London. York had a Horners’ Gild, as did Paris. Trade gilds controlled and protected their craft through the apprenticeship system, by maintaining quality and assisting their poorer members and widows.

Horn is deposited in laminated layers around a bony core separated by connective tissue. It grows throughout the life of the animal, whereas antler is shed each year. The usual practise was to remove the solid tip first, before separating the core from the sheath. One method was to soak the horn in barrels of water for a specific time depending on the season. When removed from the barrels the horn was heated before splitting with a sharp knife, prising open with tongs and putting between hot metal plates in a press and applying pressure. Placing the warmed horn into moulds before applying pressure enabled the production of horn boxes, beakers and other items. Often lathe work was involved in the making of items by horn turners.

Early descriptions defined the horner as being either a horn presser or breaker, or a horn turner, because horn working can be divided into two stages. Many items such as combs, spectacles, lantern and windowpanes were produced from semi-manufactured flattened horn and sold on to other craftsmen. These sections were called either ‘leaves’, when produced for lanterns and windowpanes, or ‘plates’ by combmakers and ‘scales’ in the cutlery trade.

Horn work includes the working of antler, cattle horn and hoof. Antler differs in chemical makeup to hoof and horn. Hoof and horn are largely formed from keratin, which is a protein; antler is bone, which is calcium carbonate and its appearance is more like ivory when the outer bark is removed.

Tortoiseshell

Tortoiseshell, the much admired decorative material, derives not from a land tortoise but from certain species of marine turtle, principally the relatively small hawksbill. Recognised by the misnomer, tortoiseshell, the substance has been renowned for its beauty since early times, principally for small articles, boxes and cases, haircombs, fans and jewellery, and ornamental veneers and inlays on furniture. According to the Shorter Oxford English Dictionary (1965), the word tortoiseshell was coined in 1601.

The substance, tortoiseshell, is referred to as a "natural plastic" or "thermoplastic", because of its ability, when heated, to be worked, stamped, pressed or refashioned, retaining on cooling, any desired shape to which it has been moulded. It can also be turned. Tortoiseshell takes and retains a high polish; it is this particular quality that endeared it to the most noble in society during the 18th. and 19th. centuries. Because of its expense, only the wealthy could afford it, hence the introduction of stained, clarified horn in imitation of genuine tortoiseshell, and later, mottled celluloid – both considerably cheaper substances.

Tortoiseshell has long been popular in China and other parts of the Orient. Wealthy citizens of ancient Rome sought decorative objects of tortoiseshell, brought to Italy from the Far East by way of Egypt. Spain was one of the first European countries to use tortoiseshell commercially in decoration and inlays, using it on chests and cabinets as early as the 15th century.