Ibarra, Joaquim (1725-1785) - He was a Spanish printer, who was born in Zaragosa and lived in Madrid. He was the first to use the card to make satin-like the printing paper through pression.

Jacobi, Morits Hermann Von (1801-! 875) - He was a German physician that invented the galvanoplasty process.
Jenson, Nicolas (? -1480) - He was a French printer; he was sent by Charles VII to Mainz with the intention to find out the secrets of typography. In 1461 he lived in Venice, where he printed more then 150 works with singular characters; this type of writting is named as "Jensonism " or "Roman"; the catholic nations of Europe adopted the roman characters while the protestants persisted in using of the gothic characters.