Impression targets question...

daemarth

New member
Simple hexagon impression question. I've attached a jpeg of an excerpt from the FIRST 4.0 book, page 200. I'm confused by the reference to the two resolutions for the hexagon target. I can see making them different sizes for different applications but not sure about what they mean by "resolution".

Any help would be appreciated,

Thanks,
Ken
 

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What it means is that the line weights are different, and the spaces between the lines is different.
 
Any idea what the standard line width and distances are for under 85ls and above 100ls? They only supplied 1 size on the CD that came with the book but it doesn't indicate what line screen it's for.

Thanks again for any additional help.

Ken
 
Did anyone ever figure this out? The ones I have are 0.0049" for the printed lines and 0.0061" for the gaps. I don't know if this is for 100 lpi and finer or for under 85 lpi.

I also have a question about what makes these work. Specifically what makes the diagonal lines fill-in for anilox-to-plate?

If you have limited space to place these targets is there a proper way to reduce their size and still have them functional? I know scaling them would not be recommended. Would removing some of the rings be acceptable? Could you create a new target as long as it had the same spacing and angles for the lines? I would want to reduced the size across of these targets but could stand to increase them in the print direction.

Any input would be appreciated.
 
Did anyone ever figure this out? The ones I have are 0.0049" for the printed lines and 0.0061" for the gaps. I don't know if this is for 100 lpi and finer or for under 85 lpi.

I also have a question about what makes these work. Specifically what makes the diagonal lines fill-in for anilox-to-plate?

If you have limited space to place these targets is there a proper way to reduce their size and still have them functional? I know scaling them would not be recommended. Would removing some of the rings be acceptable? Could you create a new target as long as it had the same spacing and angles for the lines? I would want to reduced the size across of these targets but could stand to increase them in the print direction.

Any input would be appreciated.

The FIRST control target that I have is named: "First Ctrl Tgt _Any lpi.eps" which suggests that it can be used for any lpi.

If you need to make them smaller, don't scale them but you can crop them so:
Click image for larger version  Name:	Target.jpg Views:	1 Size:	40.6 KB ID:	280546

If that won't work then you could use a different target that has the same functionality (e.g. horizontal/vertical line slur targets)

Every element being printed provides the same information regarding slur and over impression pressure setting it's just that these colorbar QC targets show the problem more dramatically and quicker.

If you have different slur indicators for different screen frequencies it may be because the impact of issues like slur is related to the line screen ruling. Put another way, as you go from coarse to fine lpi the halftone dots become closer together. If the slur amount is an equal distance for the fine screen and the coarse screen, e.g. the slur length is 60 microns, then the visual impact of the slur will be greater in the fine screen than the coarse simply because the dots are closer together and as a result there is a greater chance of them touching and joining than with a coarser screen where the dots are far apart. I.e. It's the width of the gaps rather than the width of the lines that's important. There's probably a ratio of the width of the gaps relative to the length of the slur but that's math and does not play to my strengths LOL.

I hope that makes sense.
 
Last edited:
The FIRST control target that I have is named: "First Ctrl Tgt _Any lpi.eps" which suggests that it can be used for any lpi.

If you need to make them smaller, don't scale them but you can crop them so:

If that won't work then you could use a different target that has the same functionality (e.g. horizontal/vertical line slur targets)

Every element being printed provides the same information regarding slur and over impression pressure setting it's just that these colorbar QC targets show the problem more dramatically and quicker.

If you have different slur indicators for different screen frequencies it may be because the impact of issues like slur is related to the line screen ruling. Put another way, as you go from coarse to fine lpi the halftone dots become closer together. If the slur amount is an equal distance for the fine screen and the coarse screen, e.g. the slur length is 60 microns, then the visual impact of the slur will be greater in the fine screen than the coarse simply because the dots are closer together and as a result there is a greater chance of them touching and joining than with a coarser screen where the dots are far apart. I.e. It's the width of the gaps rather than the width of the lines that's important. There's probably a ratio of the width of the gaps relative to the length of the slur but that's math and does not play to my strengths LOL.

I hope that makes sense.

perfect
 
Just for clarity...the OP's question was about flexo not offset. The control strips that Alois posted include plate as well as litho film and litho film exposure control targets.

The discussion of color control strips is a very different topic and includes, among other things, cans and worms.
 

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