The relief process is an ancient method, where the relief surface is ready for printing once all the non-printing areas have been cut away from the original surface (as in a rubber stamp), leaving the area raised to receive the ink for printing.
The intaglio process is almost the reverse of this, as the ink is held in the grooves that have been carved or etched into an engraving plate. The varying intensity of the ink is achieved by the different width and depth of grooves cut or incised by a hand-guided tool, or by etching with the application of acid after carving into a plate that has been coated with wax. After the ink has fully penetrated the recesses, the surface of the plate is wiped. The paper is then subjected to considerable pressure to transfer the ink onto the paper, from the grooves of the engraving or etched plate. This pressure leaves an indentation from around the outside of the plate. This is known as the intaglio impression.
The planographic style of printing is the most in use today. It allows a completely facile drawing to be made. With a lithograph the printing surface remains flat as the process relies on the simple principle that grease repels water. The design is drawn on to the prepared stone with greasy ink - previously a zinc crayon was used. The plate is then washed with water that is absorbed by the stone yet repelled where the image has been drawn. Printing ink is then applied, and it adheres only to the drawn image, as the water repels the ink from the rest of the plate. Then the ink is transferred to the paper through a press. Lithography is rather a complex process even though the principle is straightforward.
For multiple copies, offset lithography is now often used. These days, for individual instantaneous images, printing is usually done by ink-jet or laser-printing of an image captured by a digital camera. This of course negates the need for all the effort and skill of bygone days; however, the clarity of a digital image, no matter how skillful, will never capture the personal style of the engraving or linework of the early artists. Nor is the amazing history of early discovery imparted in modern direct representation.
The romance of early voyages of discovery were recorded by an artist and transposed by an engraver onto a plate for printing and circulation. Whether recording the charting of a newly discovered coastline or the unfamiliar flora or fauna seen there, antique prints and maps were often engraved with imaginative embellishment - either from disbelief of the sketch from afar, or personal belief in rumour of alternate knowledge. Antique prints and maps portray the story of the world’s development and sophistication.
Unlike digital replication, the fine details of original antique engravings were often hand-coloured by blending watercolours with gouache, gum Arabic, and even sometimes, gold or silver leaf, to achieve the individual style of each published image. Antique prints and maps will always be treasured, not only for the beautiful combination of science and art, but also because the rarity of each illustration on paper increases with the passage of time.
