When the Rosetta Stone was discovered in1799, the carved characters that covered its surface were quickly copied.Printers ink was applied to the Stone and white paper was laid over it. Whenthe paper was removed, it revealed an exact copy of the text, but in reverse.Since then, many copies or facsimiles have been made using a variety ofmaterials. Inevitably, the surface of the Stone accumulated many layers ofmaterial left over from these activities, despite attempts to remove anyresidue. Once on display, the grease from many thousands of human hands eagersto touch the Store added to the problem.

An opportunity for investigation andcleaning the Rosetta Stone arose when this famous object was made thecenterpiece of the Cracking Codes exhibition at The British Museum in 1999.When work commenced to remove all but the original, ancient material, the stonewas black with white lettering. As treatment progressed, the differentsubstances uncovered were analyzed. Grease from human handling, a coating ofcarnauba wax from the early 1800s and printers ink from 1799 were cleaned awayusing cotton wool swabs and liniment of soap, white spirit, acetone andpurified water. Finally, white paint in the text, applied in 1981, which hadbeen left in place until now as a protective coating, was removed with cottonswabs and purified water. A small square at the bottom left corner of the faceof the Stone was left untouched to show the darkened wax and the white infill.