Tinted glass plate negatives

Deborah Tint <dtint [at] verizon__net> writes

>I am scanning a set of 8x10 dry plate glass negatives dating from
>1910-1937.  We are scanning them to create positive digital
>"prints". In some cases the whole plate or selected areas have been
>painted on the emulsion side with a transparent deep magenta
>material.  ...

As others wrote, the red ink (brand name "Neu-Coccin") was used to
brighten image areas which otherwise would have printed too dark.
When scanning, it should be kept in mind that a simple
black-and-white scan may not do justice to the artists intention, as
it would treat grey and red more or less in the same way. I would
recommend a color scan first, which, when converted into a positive,
will show the former red area in cyan. When converting this image
into greyscale mode, the same percentages for all colors should be
used except for Cyan. Adobe Photoshop (since version CS4) provides a
tool for this. The slider for Cyan would then have to be adjusted
until the desired effect is achieved.

Klaus Pollmeier


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                  Conservation DistList Instance 25:47
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