The production of jasper, the triumphal outcome of about 5,000 meticulously-recorded trials over a period of some three years, was Wedgwood's most important contribution to ceramic art. It was one of the most significant innovations in ceramic history and has remained a staple of Wedgwood's production to this day.

The search for his jasper body absorbed much of Josiah's time and energy in the early 1770s. He was seeking a product to rival porcelain, which could be decorated in the neo-classical style and would grace the most fashionable interiors. By the end of August 1774 his experiments seemed to be bearing fruit; he was, he wrote, ‘at work upon more solid materials, & have no doubt in succeeding'.

He finally perfected it in 1775 and the composition was a closely-guarded secret; when Bentley asked for the formula, in February 1776, Josiah carefully sent him half the details, with the remainder of the information three days later in a separate letter. Industrial espionage was a very real and constant worry to the principal manufacturers. It was, Josiah wrote to Bentley, ‘...certainly the most delicately whimsical of any substance I have ever engaged with'.

Josiah's jasper was probably named after the natural rock of the same name which, like its ceramic counterpart, can vary in colour. It is a dense stoneware and, when fired at a high temperature, can be translucent to light. It is capable of taking a mineral oxide stain throughout, and Josiah carried out many experiments, grinding colours, to achieve a range of hues.

Wedgwood's choice of colours for jasper was dictated largely by the shades most favoured for neo-classical interiors by the modish architects, particularly Adam and Wyatt. White, blue and green were the first to be developed as grounds for cameos and Josiah soon followed with bas reliefs and plaques. Other colours - black, lilac and yellow - soon appeared, along with multi-coloured items, and jasper useful wares were added to the catalogues.

‘The blue body I am likewise absolute in of almost an y shade, & likewise a beautifull Sea Green, & several other colours, for grounds to Cameo's, Intaglio's &c' wrote Josiah Wedgwood to Thomas Bentley on 1 January 1775.


Jasper vase with snake handles, 1786–89

Jasper vase with snake handles, 1786–89