Conservation DistList Archives [Date] [Subject] [Author] [SEARCH]

Subject: Tinted glass plate negatives

Tinted glass plate negatives

From: Klaus Pollmeier <pollmeier<-at->
Date: Monday, April 16, 2012
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

                  Conservation DistList Instance 25:47
                  Distributed: Friday, April 20, 2012
                       Message Id: cdl-25-47-006
Received on Monday, 16 April, 2012

[Search all CoOL documents]

Timestamp: Sunday, 12-Jun-2016 11:50:37 PDT
Retrieved: Monday, 16-Dec-2019 00:05:38 GMT