Re: Societies materials etc

[NBwLNB@aol.com]

I don't entirely agree with Frank's assessment of Ragboard and high
alphacellulose boards. Both ragboard and conservation board utilize high
alphacellose fiber, are processed and bleached. Cotton has a higher percentage
of
alphacellulose content prior to processing than wood and thus reqires less
processing. However after processing, both contain alphacellulose, its only
the source that's different (cotton-wood). From a preservation standpoint,
alphacellulose is alphacellulose. As long as the processing and bleaching for
both  is alkaline and complete, and buffer is added, they're both safe.
	There are high alphacellulose papers made from cotton and wood which are
acidic. There are cotton and wood papers that are alkaline. The pH of high
alphacellulose papers and boards are dependant on the pH and conditions under
which the papers are manufactured and are not from the source of the
alphacellulose fibers.
	Museum ragboards are generally composed of a series if even plies laminated
together, ie. 4ply or 8ply. This layering gives the board excellent rigidity.
Conservation boards are generally composed of a 3 layers- two thinner layers
in which one is usually colored and a thicker middle layer.

Norman