 The importance of Altare revolves around this difference.For example, it appears that Giobatta Da Costa's invention of flint glass took place in London, while he worked for the Ravenscroft manufactory in 1674 .Altarist glassmakers operated in France, at Olréans and Nevers and one of them, Bernard Perrot went on to become master of the in Orléans, after patenting many innovative techniques  .