Create curve in Rampage

[danremaley]

Makes perfect sense to me gordo. Less is better. We currently run the two curve set-up but I would like to change it to one. The next time we do a footprint of our press, it will be without plate linearization.

Erik

I have read a lot of posts regarding linear or non-linear plates. Here's what my 40+ years of experience has taught me. Linearize the plate FIRST, no, you don't have to, BUT, if you do, then #1-we are sure that the plate is printing a 1-2-3-4% dot and #2-we "know" what a 1-2-3-4% dot area should be on press. #3-when management changes plates cause they got a 'better deal' - all you need to do is linearize the "new" plate, all your curves still work!
Also- Creo, and later Kodak use to 'over expose' their positive plates, to make sure the background came off easily to prevent tinting, on press. Many shops I visited a 50% measured 44-46%.
Dan Remaley (former GATF)

[gordo]

I have read a lot of posts regarding linear or non-linear plates. Here's what my 40+ years of experience has taught me. Linearize the plate FIRST, no, you don't have to, BUT, if you do, then #1-we are sure that the plate is printing a 1-2-3-4% dot and #2-we "know" what a 1-2-3-4% dot area should be on press.

Well a 1% etc. dot size changes according to the dpi of the recording device and the lpi of the requested halftone screen. So, in that sense, even with a curve, you really don't know that the plate is imaging a so-called 1-2-3-4% dot. That's why the installation engineers use single and multi-pixel targets instead when they calibrate a CtP device.

#3-when management changes plates cause they got a 'better deal' - all you need to do is linearize the "new" plate, all your curves still work!

True if you have mass quantities of curves. However, in my experience shops rarely have more than one and if they do they seldom have more than three. If the shop switches to a different plate there are usually other more important issues that arise.

Also- Creo, and later Kodak use to 'over expose' their positive plates, to make sure the background came off easily to prevent tinting, on press. Many shops I visited a 50% measured 44-46%.

I don't think that's correct. They would set exposure to create single pixel checkerboards with clear backgrounds. each plate/processor combination would result in a plate with a different tonal response curve. That would be its natural calibrated state and a curve would then be applied so that the plate delivered the required tone response on press.

Best, gordo