Strips showed abnormal pattern in CTP plate

[ricyk81]

My CTP house had produced a plate and attached strip patterns found.
May need some help to interpret what happen with this plate.

CTP machine: CREO trensetter 800
Energy: 5w
RPM: 185
Developer: Kodak GSP, 20degree C, 25seconds.

 

[Alois Senefelder]

Amazed -

Amazed -

Hello ricyk 81


I can't believe that you don't what these "Strip Patterns" are for, they are --


Plate Control Targets - What is a Plate Control Target?

"Plate control targets are highly precise test images for diagnosing, calibrating and monitoring

imaging steps in the graphic reproduction process. As the name implies, plate control targets

are designed for platemaking" The Lithographic Technical Foundation



Regards Alois

PDFs

 

[maxon]

I believe he refers to the hairlines across the plate - lower control target, deep shadow patches. Ricyk81, is that the problem ?

 

[ricyk81]

Dear all,

Thanks. I am sorry that i did not post my question.
Actually, as i understand that the strips for the 6 dots (1x1, 2x2,3x3...) should showed equally if the exosure and developing parameters are optimum. But also it is better that 1x1 and 2x2 dots are darker than it base and 3x3 is equal in order to have better ink-water balance.
But, now the plates showed 1x1 is darker, 2x2 is equal and 3x3 is over...this is confusing me.

 

[VladCanada]

You understand incorrect.
This strip (DigiControl Wedge) to be used for finding proper exposure level of CTP.
Depending on the type of plates, 1X1 or 2X2 field should be invisible (matched to background).
If you see some targets lighter than background - overexposure.
Darker - underexposure.
So, if you can't see target #4 or 3 - you have to increase exposure level.
If tagets 1, 2, 3, 4 lighter than background - exposure level needs to be decreased.