CALCOGRAFIA. — A word formed from the Greek terms χαλκός (copper) and γράφο (I write), properly denoting the technique of engraving by incision into copper. From the mid-sixteenth century through the whole of the nineteenth century, it was widely employed for book decoration, especially on title pages, until the ascendancy of etching and the simplification of typographical ornaments gradually brought about its disappearance.
The name also came to denote both the workshops in which copper was subjected to the chemical processes necessary to produce c., and collections of original copperplates. Among the latter, the “Roman papal c.” acquired great renown; founded in 1740 by Pope Clement XII following the purchase of the copperplates belonging to the De Rossi family, they also included those of A. Lafrery. Transferred to the Italian State after 1870, it took the name of “royal c.” It now contains approximately 20,000 engravings.
In present-day printing technology, some designate by the term “rotary c.” (German Tiefdruck) the process commonly known as “rotogravure,” which is widely used for illustrations outside the text and for certain types of illustrated newspapers. It is produced by transferring the design, through the use of a special sensitized paper, onto a copper cylinder, on which the engraving is made; the cylinder then prints the image onto the paper like that of an ordinary rotary press. For c. in art V. INCISIONE.
#### CALCOLO : V. MATEMATICA.