Please see below for instructions on how to count different kinds of material at Houghton:
Volumes
General: Count cover to cover as separate pages, not as openings.
...
Fold outs: Count each fold to determine number of fold outs.
Scores
General: Count cover to cover as separate pages, not as openings.
Letters
General: Count only the sides with text, drawings, etc.
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Overlays: Count twice – once for image with overlay & once without.
Manuscripts
General: Count both blanks and pages with text, drawings, etc.
Overlays: Count twice – once for image with overlay & once without.
Photographs
Count rectos.
Count the verso only if stamped or non-library writing on the back.
Drawings
Count rectos.
Count the verso only if non-library writing on the back.