During roughly the second half of the Twentieth Century one cheap alternative for printing oversize music scores was to use the kind of blueprint equipment normally used for architectural drawings. In this case, the image is made not with ink on plain paper, but photographically, on specially treated photosensitive paper.

This type of printing, known as the diazo process for the type of chemical reaction that produces the image (and sometimes called “Ozalid” after a specific brand name), was a boon to small publishers of large scores. However, the resulting products are problematical for libraries.

First of all, the paper remains photosensitive, particularly in the ultraviolet range. When exposed to light for long periods the scores will darken. Also, the photosensitive material is alkaline. This means that if a diazo score is inadvertently deacidified, the images may be lost. Finally, anyone familiar with scores printed this way will remember the strong smell of ammonia that they produce over time.

Diazo scores were also often bound as cheaply as they were printed, with comb bindings, or printed in long strips that were then glued or taped to form stiff laminated “pages” that have odd and often weak central attachments.

All of this means that on the whole the best thing to do with a diazo score is to photocopy it onto plain paper (now that this is a cheap alternative for pages up to 11×17 size) and throw the original away. While this goes against the grain of a preservation librarian, it does satisfy copyright requirements.

If the original is to be stored, either because of artifactual value or because it is not being duplicated, the best storage conditions will include darkness and acidic surroundings. Filing many such scores together in large file drawers will work, as will wrapping individual scores in heavy acidic paper before shelving them in dim light.

Alice Carli, formats
Last updated: February 16, 2008, at 08:04 PM EST

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