Definition of "jaconet"

It would be mortifying to the feelings of many ladies, could they be made to understand how little the heart of man is affected by what is costly or new in their attire; how little it is biased by the texture of their muslin, and how unsusceptible of peculiar tenderness towards the spotted, the sprigged, the mull, or the jackonet.

1803 (date written), [Jane Austen], chapter X, in Northanger Abbey; published in Northanger Abbey: And Persuasion. […], volumes (please specify |volume=I or II), London: John Murray, […], 20 December 1817 (indicated as 1818)

It really was beautifully executed, more like a forgery than a copy, for the copyist had laid it down on a jaconet backing and had even added a cachet de vente, a couple of collectors’ marks and a museum reference number.

1979, Kyril Bonfiglioli, After You with the Pistol, Penguin, published 2001, page 321