Developed Plate Analyzing TIP

[printPlant]

Hi
how to check plate after developing that is to be good develop or poor develop.

 

[viswanaathan_r]

There are control strips available - print these in the non image area of the plate - you can have a visual confirmation of the quality of developed plate. Check with your plate supplier / prepress guy.

 

[VladCanada]

It's very dependable on type of plate technology: conventional analog or digital thermal, photopolymer, lithostar, thermofuse...
Absolutely incompleted question.

 

[Alois Senefelder]

Plate Control

Plate Control

Hello fellow Lithographers and Pre Press


A PDF re Plate Control Targets



Regards, Alois

 

[printPlant]

thanks for all members....your best solutions

 

[minch]

"wedge"

"wedge"

Hi how to check plate after developing that is to be good develop or poor develop.

I presume you are talking about a CTF (computer-to-film) workflow where you are using a PDF (print-down-frame) to expose a positive or negative plate with postive or negative film.

Your plate supplier should be able to supply you with a "film step wedge" and settings for the plates you are using.

You place the "wedge" onto the plate after you have positioned your film or foils onto the plate. You expose the plate and the wedge leaves an image just as the film leaves an image.

The "wedge" is a series of graduations from light to dark and each graduated step has a number on it.

When you have exposed & developed the plate you will see these graduations, but they will either be solid or clear. Your brand of plate will have a particular setting to aim for such as solid 6 or clear 2

Your plate supplier will be able to supply you with the wedge and the settings for your brand of plate.

Nice to hear some people are still doing it the hard way - most of us have been spoilt with CTP (computer-to-plate) no film required.

 

[VladCanada]

minch, even some photopolymer CTP plates need Stoufer wedge to find a proper laser exposure value of CTP.
Just reminder

 

[printPlant]

Use a drop of Acetone
I believe the "standard" method for verifying if a CTP plate is fully exposed and developed is to put a small drop a Acetone on a corner of the plate on an image-less area.
After the liquid evaporates, there should be no noticeable "borders" of that vanished drop.
Usually a very faint thin border is permissible, but darker borders indicate that there are traces of emulsion on the areas of the plate, that should have come out clean.
Assuming that the plate exposure is OK and the developer solution is new or in good working order, and there are still traces of emulsion, the remedy is to increase processing (slower machine speed and/or higher temperature for the developer).
This is probably typical to over-dated CTP plates.
I think, this is best solution for this problem.....Good luck.