~~~~~~~~ Excerpt from the Guide to Platinum-Palladium Photographic Printmaking by Jeffrey D. Mathias ~~~~~~~~
No part of this document may be reproduced in whole or in part without the express written permission of the Author.
 

Building the Positive

With the original negative in the enlarger, select a size which will leave at least a ½ to 1 inch wide boarder on the size of film used.

Focus carefully on a piece of film in the easel.

TEST:  [Note: This is done in tandem with the shadow mask test]

                Note: 4127 film can vary widely from batch to batch.  Choose part of the image that has both
                          extreme light and dark values.
                Note: When exposing, it is much more accurate to 1) hold a card I front of the lense;  2) turn on
                          the enlarger;  3) remove the card and start the timer simultaneous;  4) when time is up,
                          replace the card;  5) turn off the enlarger.
                Note: Instead of a timer, metronome tics can be counted from a device that varies the time
                          between tics directly as a function of the intensity of the lamp intensity.  A schematic for
                          such a device is found in this manual labeled “light intensity monitor”.


Repeat above TEST steps until the positive looks right when registered with the shadow mask.  The positive and shadow mask should look pretty much like the print except that the dark values will be blacker in the print.  When done properly, the image will have a “glow” to it.  A matrix could be made for this process; but there are so many variables, such a matrix may not be practical.  After several hundred built negatives, one should begin to understand the relationships between the finished print and the positive, negative, and masks

Enter date, image size, f-stop, exposure time, developer concentration and time into notebook.

WARNING:  Once the enlarger is set up do NOT move anything, do NOT focus, do NOT change f-stop,
                    do NOT move easel, do NOT bump enlarger.  BE  CAREFUL ! MAKING THE POSITIVE:
 

MAKING THE POSITIVE:

After rinsing the positive and shadow mask may be viewed in registration to check if fine adjustments or dodging or burning are required.

        Note: Film can be saved by making a RC print to first check for dodging and burning.  Also film
                  processing can be calibrated using RC paper thus saving film.  One must establish the
                  relationship between the two materials.  If one has mastered the normalization technique
                  used with the Matrix, this will be quite simple.

 

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