ENGRAVER.
1. One who practices engraving.
2. The specialist who engraved on the stone in lithographic engraving: a technique which was popular when lithography had a larger industry than it has today. (See lithography)
3. In photogravure, the line engraver specializes in the etching process.

ENGRAVING. (See printmaking techniques)
In a general sense, the word covers all works of art or industry (both plate and impression) which use incision as means of marking the design.

ENVIRONMENT, ENVIRONMENTAL FACTORS.
In the context of conservation and deterioration studies, these terms refer to physical effects of the environment, such as humidity, temperature, light, pollutants of the atmosphere.

ETCHER.
An engraver who practices the etching process.

ETCHING. (See printmaking techniques)
One of the most important methods of intaglio engraving.

ETCHING "A la Plume".
A method of intaglio printing in which a pen and ink drawing is made on a clean metal plate. When this has dried, the entire surface is covered with a light aquatint ground and placed in an acid bath which has the effect of removing the ground where it is to be found over the ink. The plate can then be bitten as for a normal etching. The technique is difficult to do well, and was much improved by the sugar-lift process.

"EX-LIBRIS".
An owner's mark placed in a book, usually on the inside of the cover. Engraved ones have been used since the fifteenth century.

EXPANSION.
The result of change in the dimension of a sheet of paper due to excess humidity; more pronounced across the grain than with it.