Scrim is used to strengthen plaster coving, and other fibrous plasterwork. Scrim is a type of open weave cloth and can refer to textiles made from cotton, flax, and Jute. The Scrim is added to strengthen the coving between the first and second layers of plaster and must be added while the first plaster is still fluid enough to incorporate the scrim and then join seamlessly with the second plaster layer.
When Fibrous Plaster was patented by the French Modeller Leonard Alexander Desachy in 1856, part of the patent specification read ‘flat surfaces are strengthened with canvas, wires, hooks, or pieces of wood may be inserted whilst the plaster is in a fluid state', in truth whilst he may have been granted a patent he had done no more than revive an existing process, but that is another blog post.
Jute scrim soon became established as the material of choice for reinforcing fibrous plaster coving and mouldings and is still used in the manufacture of coving and mouldings today, it was cheap and strong and there was in Victorian times, a huge Jute spinning industry based in Dundee, which at its height had 60 mills employing 50,000 people. Jute had been imported from what is now Bangladesh by the British East India Company for 150 years, before a process of mechanically spinning the Jute fibres was first perfected in Dundee. Dundee was a Whaling port and Whale oil was integral to the new spinning process.
Gradually the Scottish industry declined as Jute mills were set up in India, often by expatriate Scotsmen and by 1900 the Calcutta Jute industry had overtaken the Scottish. Nowadays Jute is the second most produced vegetable fibre after cotton, with Bangladesh the world’s largest producer producing nearly 3 million tonnes in 2011.
The manufacture of plaster coving is and has only ever been a very minor outlet for Jute; it has and continues to be used in furniture manufacture, sacking for raw cotton and coffee beans. Jute was used to make the sand bags for the trenches of both world wars. Over one billion Jute sand bags were exported from India for the trenches of World War 1. Jute fibre is biodegradable and today is being used in new industries such as the car industry to help manufacturers reach their recycling targets.
