When printing begins, the stone is kept wet and then covered with oily ink. The area where the original image was drawn will then attract the oily printer’s ink. But the blank areas will reject the ink and will instead attract water. This method works because oil and water do not mix.

STEVE EMBER: The lithographic process was invented in the late eighteenth century by the German writer Aloys Senefelder. Mr. Senefelder wanted to find a low-cost way to reproduce his plays. But he soon realized the artistic possibilities of his lithographic printing method.

French artists in the nineteenth century became very interested in using lithography. For example, the French artists Honoré Daumier and later Henri Toulouse Lautrec were masters of this process. They would draw directly on the stone and a printmaker would do the rest of the work. Lithography is used commercially as well. Picture books, newspapers and packaging all over the world are printed using this process.

BARBARA KLEIN: Etching is yet another printing process. With this method, the printmaker cuts, or etches, an image onto a piece of metal. The artist uses a fine sharp knife to cut through the metal. This metal form is chemically treated before being covered with ink and then pressed onto paper.

Some artists like this process because they can draw on the metal as easily as if they were using a writing pen. Experts say the greatest artist ever to use this method was Rembrandt. This Dutch artist lived in the seventeenth century. The detailed perfection of his etchings of nature and religious stories is extraordinary.