A full sheet of handmade paper has 4 deckle edges. Mouldmade papers have 2 true deckle edges, on the sides. The weight of paper is traditionally measured in pounds weight per 500 sheets of a certain size paper. The whiteness of paper varies according to the fiber color, cleaning, bleaching drying and sizing operations, etc. Bleaching has distinct disadvantages.
Paper can yellow, become brittle, and deteriorate if traces of bleach are left on the fibers.
During this century, there has been a tendency to artificially whiten papers using optical brightening agents. These initially produce a whiter sheet, but the color changes markedly over time and will yellow. This will not happen to paper made with the natural shade of the fiber. Acid free boards should be place on top and bottom of the flat file to avoid migration of acids. Wooden flat files are better than metal for paper storage as they stabilize relative humidity, and do not rust.