The ‘Adam chimneypiece’ is an icon of neo-Classical taste that is still popular today. Yet the history of  how they were mass produced in ‘pine and gesso’ is not widely known.

Fine chimneypieces were generally carved out of marble or lime wood, until growing demand during the Georgian building boom began to outpace supply, exacerbated by the embargo on importing marble during the Napoleonic Wars. So the Adam practice pioneered the production of a cheaper, less labour intensive alternative, made of pine and what was known as ‘Adam’s composition’ a putty-like substance mixed to a secret recipe that William Adam claimed he got from a Swedish philosopher, which could be cast from moulds to create decorative ornament then applied to timber frames.

These chimneypieces were exported abroad, often as ballast in ships returning empty from Glasgow or Leith. Soon, they were being widely copied on the east coast of America, where their distinctly Scottish interpretation of Classical detail spare and concise by comparison with the heavier ornamentation of their English counterparts manufactured by firms such as Wolstenholmes of York became as much a symbol of the American Federal style as it was of Adam neo-Classicism.

Today, there are plenty of cheap ‘repro’ chimneypieces on the market (many made in China), but one company has revived the authentic composition recipe and is producing high-quality facsimiles of the Adam originals, using the traditional method. In an echo of history, Thistle & Rose was founded to meet a supply problem this time resulting from the growing fashion for restoring old houses and reinstating fittings of decent quality.

The catalyst was a visit made in 1990 by the company’s co-founder, David Black, to Sir Henry Raeburn’s house, where he was horrified to discover that all the chimneypieces had been stolen. ‘I felt it was an appalling loss of Edinburgh’s heritage, but nobody seemed bothered. Thefts were rife in the New Town, and I thought that if affordable, good-quality copies were available, the problem could be reduced.’ So, after an abortive attempt by the Edinburgh New Town Conservation Committee, ‘I decided to produce them myself’. Coincidentally, the cabinetmaker Kim Roberts, who was working for Mr Black, said he had always wanted to try making one, ‘so I gave him an original I was about to install and told him to see what he could do. After researching and adopting the original recipe, he came up with a beautiful copy’. They established their ‘atelier business’ in Hawick in the mid 1990s, and Mr Roberts now works here with four other craftsmen.

They make the frames from Scots pine, each tree carefully sourced, sawn locally and traditionally seasoned. Moulds are made by taking casts from original details. ‘You have to get to know your mould. Each one requires different handling, and it’s a knack pressing in the warm putty a mix of chalk, animal gelatine, water, linseed oil and rosin.’ It is ready to be removed after a few minutes, when it is cut off its backing and put into a fridge. When all the details are ready, they are trimmed, and then stuck onto the sealed and sanded frame. The consistency of the compo is similar to Cheddar cheese, but, after some days, it becomes brick hard. If painting is required, chimneypieces are sprayed in the workshop and then touched up by brush; other finishes include marbling, glazing and gilding.

Thistle & Rose manufactures 12 designs copied from historic examples, which can be adapted to suit individual specifications; each costs about £2,000. They also make one-off facsimiles, and restore and clean originals. Mr Roberts has another business too, Chisholm Antiques, which makes and restores furniture and carves chimneypieces in lime wood and mahogany.

Thistle & Rose 01450 376928; www.thistleandrose.net

Top tips

  • Use only a damp cloth to clean; water discolours and damages gesso
  • 18th-century composition pieces were nearly always painted to protect the gesso
  • Never use wire wool to remove old paint. Use special tools and controlled chemicals, and, ideally, a professional