After printing the same wedge - if you want - up to four times (of course you should take note of the settings maybe writing them down on the Pictorico sheet itself with a marker) we are going to coat some paper and make our first print.
If you have built your UV unit similar to mine, your printing time should be around 4 minutes. Coat the paper with pure palladium and one drop of 2.5% Na2 and expose the sheet for this time (as said earlier if you want to standardize your printing with one drop of 5% Na2 you can, just do it now and do not change it anymore). Develop, clear, wash and dry and you are ready to assess your first "print". The procedure is quite straightforward: notice on the print the first square that is not pure white and write down its number, the same for the first one which is not pure black. These are our limits when preparing out images, or in Zone system terms, these are your Zone IX and I. These two zones as said are the limits but please keep in mind that you have to shift the zones one stop to get useful details in the print (e.g. Zone VIII and Zone II, the lightest and the darkest zones in the texture range). To easily find these zones, I usually cut a corner from the print and punch two holes, one in the black brush strokes and the other in the clear paper. I then pass over the squares to compare the densities. Please do this in normal lighting conditions, not under a strong light to see better.
In my case, and hopefully in a similar way in your tests, I got Zone IX = ~8/9% and Zone I=~78% with a 4 minutes exposure. Why I am happy with these results. Because I have several pure white and pure black squares above and below this range, which means that my time is correct as well as my contrast. If you do not, for example if the 0% square is not white but slightly darker than the paper outside the brushed area it means (assuming that the print has cleared well) that your time is too long (or there is a problem printing your negative i.e. not enough density). Conversely, if none of your blackest squares are not as black as the brushed borders your time is too short. Especially with pure palladium the brush strokes should be real black, like ink. Lower the light panel if they are not. If you have built the exposure unit as suggested, you can raise or lower the light panel to correct the timing, being careful to stay around four minutes (remember that if you double the distance, the light received will be four times less). Only one stop more is already eight minutes, two stops are 16 and so on, and this is not convenient when printing for business. Conversely keeping the UV tubes too close to the paper would give unpractical short times (for dodging etc.) and probably would show light stripes from the tubes on the print.
I would stick to this test in pure palladium for now. Of course, should you decide to go for a classic 50/50 solution with platinum, for example, you will have to repeat the test with this mixture (same thing if you plan to print with different papers).
Now back to Photoshop to create your own printing curve. Load your favourite grey scale image, a landscape, a portrait etc. with good tonality, plenty of detail in shadows and highlight, like my lake in the next page for example. Go over the image with the eyedropper, for example on shadows where you still want good details. Photoshop will probably indicate a value of 80% or more. But by checking the printed wedge you can see that 80% will print almost pure black, so this value needs to be tweaked. Likewise pass over well detailed highlights, the reading will be too low, such as 30%, while you know that your Zone VII is around 10%. So the next thing to do is to apply a curve to the image to match the palladium curve in the darkroom. Create a new Curve Adjustment Layer. Basically as a starting point you just grab the central part of the curve, which of course is a flat line (from top right, shadows, to bottom left, highlights) to s
If you have built your UV unit similar to mine, your printing time should be around 4 minutes. Coat the paper with pure palladium and one drop of 2.5% Na2 and expose the sheet for this time (as said earlier if you want to standardize your printing with one drop of 5% Na2 you can, just do it now and do not change it anymore). Develop, clear, wash and dry and you are ready to assess your first "print". The procedure is quite straightforward: notice on the print the first square that is not pure white and write down its number, the same for the first one which is not pure black. These are our limits when preparing out images, or in Zone system terms, these are your Zone IX and I. These two zones as said are the limits but please keep in mind that you have to shift the zones one stop to get useful details in the print (e.g. Zone VIII and Zone II, the lightest and the darkest zones in the texture range). To easily find these zones, I usually cut a corner from the print and punch two holes, one in the black brush strokes and the other in the clear paper. I then pass over the squares to compare the densities. Please do this in normal lighting conditions, not under a strong light to see better.
In my case, and hopefully in a similar way in your tests, I got Zone IX = ~8/9% and Zone I=~78% with a 4 minutes exposure. Why I am happy with these results. Because I have several pure white and pure black squares above and below this range, which means that my time is correct as well as my contrast. If you do not, for example if the 0% square is not white but slightly darker than the paper outside the brushed area it means (assuming that the print has cleared well) that your time is too long (or there is a problem printing your negative i.e. not enough density). Conversely, if none of your blackest squares are not as black as the brushed borders your time is too short. Especially with pure palladium the brush strokes should be real black, like ink. Lower the light panel if they are not. If you have built the exposure unit as suggested, you can raise or lower the light panel to correct the timing, being careful to stay around four minutes (remember that if you double the distance, the light received will be four times less). Only one stop more is already eight minutes, two stops are 16 and so on, and this is not convenient when printing for business. Conversely keeping the UV tubes too close to the paper would give unpractical short times (for dodging etc.) and probably would show light stripes from the tubes on the print.
I would stick to this test in pure palladium for now. Of course, should you decide to go for a classic 50/50 solution with platinum, for example, you will have to repeat the test with this mixture (same thing if you plan to print with different papers).
Now back to Photoshop to create your own printing curve. Load your favourite grey scale image, a landscape, a portrait etc. with good tonality, plenty of detail in shadows and highlight, like my lake in the next page for example. Go over the image with the eyedropper, for example on shadows where you still want good details. Photoshop will probably indicate a value of 80% or more. But by checking the printed wedge you can see that 80% will print almost pure black, so this value needs to be tweaked. Likewise pass over well detailed highlights, the reading will be too low, such as 30%, while you know that your Zone VII is around 10%. So the next thing to do is to apply a curve to the image to match the palladium curve in the darkroom. Create a new Curve Adjustment Layer. Basically as a starting point you just grab the central part of the curve, which of course is a flat line (from top right, shadows, to bottom left, highlights) to s