Pulp Fiction & Facts:
- Trying to nail down a date and place of manufacturer of a pre 20th Century sheet of paper by the number and placement of laid and chain lines will just frustrate you: The reality is that there has never been consistency in these measurements.
- Foxing: Stains, specks, spots, and blotches in paper. Contrary to popular belief foxing is not a good indicator of acidic paper or of the paper’s age. Although the chemistry behind foxing is not well understood, its seems to be from the interaction of certain fungi with iron present in the paper. Relative humidity and temperature are two of the factors most likely to promote foxing.
- Often it is said that any wood pulp paper from the 19th Century is acidic. However, while wood was the basis of many papers from the earliest years of the 19th Century, it was not until the development of the sulfite process in the late 19th Century (1880) that acidic paper became an issue. Problems with acid prior to this date (generally noticeable at the edges of the paper) are generally caused by acid migration from leather or hydrochloric acid from air pollution during the industrial revolution.
- Since foxing is not an accurate identifier of acidic paper, it is important to become familiar with the properties of acidic paper. The two most telling signs is discoloration (from yellowing to a rusty brown color), and a brittle feeling to the paper. Also, acidic paper is prone to staining even non-acidic paper if it is in contact with it over time through the process of acid migration. This is often seen when acidic newspapers have been tucked in the pages of an old book.