I don't know how many people are familiar with Todd and Zakia's book "Photograpic Sensitometry" but when I was in graduate school it was my 'bible' for photographic technique.

Anyway I would like to quote from the book a passage that further emphasizes my technique of visual estimation of paper response, rather than reflection sensitometry of paper.

Information about log E paper ranges needs to be reliable. Such information is best obtained by a test in the actual printing conditions, rather than relying on manufacturer's data which are only representative of a product. This information can be obtained by printing a negative step tablet in a standardized way with a controlled light source and at a know magnification if a enlarger is being used. A visual examination of the print of the step tablet is usually sufficient to establish of the range of log E over which the paper responds."
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