Uvitic acid is obtained by oxidizing mesitylene or by condensing pyruvic acid with baryta water. Barium hydroxide ("baryta") was known to alchemists, who produced it by heating barium carbonate. The light-sensitive silver halide emulsion is then coated over the baryta layer. The term "baryta" derives from the name of a common barium sulfate-containing mineral, barite. More recently, baryta has been used to brighten papers intended for ink-jet printing.