Nanoparticles save paper

Bob Cox sent over This One from Nature on calcium hydroxide grains just 200 millionths of a millimetre across that are helping preserve historical documents. The nanoparticles of what is commonly called slaked lime penetrate between paper’s fibres. They combat the ravages of acids introduced when paper is made, without altering documents’ apperance. The technique is cheap and green and could also be used on canvas.