Recent content by martin.weberg

Hi Lucas Sorry I'm picky today ;-) But extrapolating is always sketchy, since you know nothing about the device/process/model behavior beyond the sampled range. For sure you mean interpolation, right? Martin Weberg

Hi Lucas The problem does not lie in how many samples you've got. Really, you can't get too many (there are however practical/economical issues in using too many samples, this is where statistics come to play). The trick is how you model the device from measured samples (using smoothing...

Gordo, do you mean isometric curves like those described in this study? http://www.doplganger.com/resources/TAGA/TAGA_2004.pdf Or, can you point me to another reference? Martin Weberg

He's pretty clear on that: "theoretical target from common data sets conforming to the same standard, such as Fogra 39 or Gracol 2006" Martin Weberg

Great! Martin Weberg

Hint: ISO 12647-2:2004 Annex B Figure B.1 and B.2 (together with Figure 2) Martin Weberg

If you mean spot colours there's no easy way. It would require spectral data and advanced algorithms. See: "http://cias.rit.edu/~gravure/tt/pdf/pc/TT8_Predicting Spot-Color Overprints.pdf" for a related study. Martin Weberg

If they are printing with spot colours and post-laminate I'd recommend following method. Test run. First, match print and reference (Pantone swatch). Gradually decrease bellow best match, then increase above best match. Key is documenting the wet densities and marking the printed sheets...

Are they printing using the specified spot or CMYK colours? Martin Weberg

Based on your first question I recommend you to hire a consultant. Many things might go wrong and when it does you need to be able to analyse it.

Hi again, Since you're using the strip, I guess you have licence for it (second-hand should make no difference). Evaluation of the other fields on the strip are quite self evident. Try to contact Heidelberg. Martin Weberg

Hi The really quick answer is that for an optimal process the middle triangle (or checkpoint) should blend in with the background. They are of different screens but have the same tonal value in the middle. The small dot screen is much more affected by production variances then the zigzag...

FYI, FOGRA29 was replaced by FOGRA47L some time ago. Martin Weberg

Then you'll be fine. Slur marks are really simple to make. I like the design with radial rays. Martin Weberg

I would definitely align the CMYKRGB3C step wedges parallel to the printing direction. Keeping all percentages inside the same ink zone for obvious reasons. Then I would add slur marks. Martin Weberg