Archival Quality What is it?
The word "Archival" seems to signify the highest quality available to prevent degradation of your valuable comic books and other paper-based collectibles. Unfortunately, there is no national standard to regulate what true "Archival Quality" is. This means that any sleeve can be called Archival even though it may contain plasticizers and other melting agents that can and will migrate into your precious collectibles turning the pages yellow over time. However, the U.S. National Archives and the U.S. Library of Congress have both issued specifiications for which we follow.
According to the US Library of Congress, the most preferred material for preserving valuable documents is uncoated archival quality polyester film, such as Mylar® type D. or equivalent material Melinex® 516.
Mylar® is an exceptionally strong transparent film that is resistant to moisture, pollutants, oils, and acids. It contains no volatile chemicals which will migrate to the surface of the paper and cause damage. With a life expectancy of hundreds of years, Mylar® will outlast most other plastics.
In addition, along with the brilliance and clarity of Mylar® which enhances the appearance of any paper collectible, it is an effective barrier against acidity which is the primary cause of paper deterioration.
Mylar® is a registered trademark of DuPont Teijin films. Their brands of archival quality polyester films are Mylar® type D and Melinex® 516 of which they are exclusive manufacturers.