Steps to make an etching
Every day, dozens of prints leave the presses of the National Museum Art Workshops. The collection of the Louvre's Chalcography consists of more than 14,000 print matrices, the oldest date from the 17th century. These are copper plates engraved intaglio: the pattern is embedded in the metal (unlike savings engraving, where the subject is in relief). The chisel and etching are the two most common engraving techniques in the collection, where aquatints, pencil patterns, drypoints and gravure prints are also found.
The collection of the Louvre's Chalcography also includes about a hundred wooden (xylography) and stone (lithography) matrices. For technical reasons, these boards are not used.
Printing of intaglio engraved plates
To print a plate, the printer first removes the varnish that protects it and ensures its proper preservation when it is in storage. After cleaning it, he makes sure that it is in good condition, in order to ensure a quality print and not to damage the plate. Once this work of recognition has been completed, the printing process begins.
First, the printer generously inks the matrix: the entire surface of the metal must be covered with a thick ink, made of linseed oil and pigments and specifically designed for intaglio printing. It is distributed with a roller and then with a leather pad. To facilitate this operation, the engraved plate is placed on a heated table to make the ink more elastic. The printer ensures that each size is well inked.
Wiping: the most important and delicate step
Using a muslin fabric, called tarlatan, the printer removes the excess ink, gradually making the pattern reappear. The unengraved parts are cleared of ink, which must remain housed only in the sizes. The printer ends the operation with the palm of his hand, covered with a little Spanish white, to remove the last traces of unwanted ink. The bare metal must then shine like a mirror. This last operation, called "paumage", requires great dexterity.
Transferring ink to paper
The printer then places the inked plate on the press plate in an intaglio format. He covers it with a sheet of paper, previously moistened to make the fibre more receptive to ink. The whole is protected by thick felt, which dampen the very high pressure of the machine. By a horizontal movement, the matrix and paper pass under the press cylinder. The ink is transfered to the paper.
The printer can then remove the sheet and reveal the print run. Due to the high pressure exerted on the wet paper, the sheet keeps a bowl, which corresponds to the perimeter of the matrix: this is called the printing plate.
The printed proof, still wet, is placed between blotters and thick cardboard. The printer can re-ink the plate and repeat each operation to obtain another print run.
Final step: checking and installing the stamp
After forty-eight hours of drying, each print is carefully examined to ensure that the print is free of defects. Prints that do not meet the quality requirements of art studios are systematically discarded. The last stage of the manufacturing process then takes place: the installation of the dry stamp of the Louvre's Chalcography. This embossed mark, "embossed" on the edge of the print, certifies the quality and authenticity of the print.