@Phil
Yes you are a prime candidate for a one curve workflow.
As Steve said, work with your local Agfa rep. to return to the installation settings. That puts your plate imaging into a known output condition. Start a log book to record your plate's tone response once it's been setup by the Agfa tech.
Start with the basics, the "old-fashioned" way. You can always make the process more complicated later.
• Decide on a tone reproduction target for your presswork. I suggest the appropriate curve from ISO 12647-2.
• Create or use an existing test form that includes individual CMYK tone ramps in 10% increments.
• Run the press to solid ink density with plates that that have no curves applied to them - they're straight out of the Agfa non-processor as set up by the Agfa technician. If your test form includes images - ignore them. Just print to the SID numbers.
• Measure the resulting tone values on the press sheet and plot the four curves on graph paper. They should have a similar shape and should closely nest together. If the curves are good then you can build a tone reproduction/press curve that changes the natural tone response so that it aligns with the appropriate ISO curve.
• If the natural curves don't have a similar shape and/or do not nest - you may have a press or ink issue that needs to be corrected before you can build tone reproduction/press curve.
• Apply your curve to a new set of plates and run to the same SIDs as you did on your first press run.
• Measure the resulting tone curve. It should now align with the ISO target you chose.
That will give you tonal alignment to ISO
If your ink hues conform to ISO-12647-2 your presswork should now also align to an ISO proof.
AS you move forward, the tone values on plate that your curve creates become the process control number for plate imaging monitoring. E.g. If you curve results in a 43% tone on the plate where you ask for 50% then whenever you ask for 50% you should always get a 43% tone (plus/minus whatever Agfa says is their acceptable tolerance).
The idea is to break your print process down into its basic building blocks. Perhaps create a workflow chart to help get your process organized rather than trying to do it in your head. Stabilize, standardize, and create specifications (and tolerances) for each of those individual blocks. Then if something goes wrong it is much easier to determine which of the building blocks has varied, and in what way, from its specification.
best, gordon p
