Tarred Jute Twine

This donut-shaped ball of fine, high-twist jute twine has been tarred to make it strong and weather-resistant, giving it the warm, smoky and earthy smell of old ships. Jute is not intrinsically the strongest or most water-repellent natural fibre, and is surpassed by sisal, hemp and ramie in tensile (pulling) strength, for example. As a result, jute twine is often waxed or tarred to weatherproof it and improve the fibre’s strength and durability for demanding outdoor applications. 

Historically jute and other natural fibres were treated with pine tar to protect them from water, rot, mildew and UV damage and to enhance their grip, making them suitable for maritime applications. These sailors’ twines were called ‘marlines’, with the name coming from the act of marling, whereby thinner tarred lines like this one were used to bind the ends of larger ropes to stop them from fraying and unravelling. Nowadays twines and ropes are preserved and strengthened using a range of different materials, including waxes, polymers and tars made from wood, peat, coal or petroleum. 

Jute is often referred to as hessian or burlap when it is in its woven fabric form. It is made from the bast and core fibres of plants of the Corchorus species that are grown commercially in India and Bangladesh. It is one of the cheapest natural fibres and is grown in quantities second only to cotton. In order to turn this plant into a useable twine, the silky, flexible fibres are separated from the woody stalk by one of two methods. Fibres might be isolated by biological means, for example by allowing the plant to rot in the field or by ‘retting’ it in a shallow pond: in both instances enzymes produced by bacteria and moulds degrade and remove woody and gummy materials, freeing the fibres. Alternatively, fibres might be separated by mechanical means: at the simplest level, stems might be beaten it on a rock, or more complex mechanical machinery might be used to roll, squash, sieve or cut the fibres from the stems.

Besides its maritime heritage, tarred jute twine is also a favourite of gardeners (including Monty Don of Gardeners World fame) for tying everything from beanstalks and bamboo to gazebos. According to gardeners’ lore, it is unpalatable to birds who might want to unpick it for their nests, and slugs and snails won’t cross it.

This twine ball is currently being replicated in cast bronze and iron by expert metalworkers Steve and Necole from Dorset-based foundry Coles Castings. These examples of the lost wax casting process will be coming to the Materials Library catalogue soon!