Hexachrome sreen angles and dot pattern issue.

[jmiami]

We've printed a pantone hexachrome test sheet yet only the PMS spot colors come out correct, the photos are not so good. I've done a little research and wonder what everyone in-the-know about this subject thinks.

- here's what I found.

The potential moir? problem is even worse in the case of "hi-fi" colour where instead of the traditional four CMYK plates there can be up to eight plates. The most common example of hi-fi colour is Pantone's Hexachrome which as its name suggests uses six colours, with additional green and orange plates set on the same angles as magenta and cyan. If any plate is even 1? out of registration your high quality print-run can be ruined. (in Quark the default output is correct in regards to that)

---on the RIP there's a dot pattern called Hexachrome Chain
I found this from google: http://www.globalgraphics.com/techno...lequin/hsl.pdf
I think this would resolve the problem of registration we're having.

Anyone have other experiences with this process?
-

[Sparky]

Only calling on my past experience with multi color "touch plates" using an extra hit of red (magenta) or blue we experimented with the "oval" shaped dot pattern, square dot, round dot, etc. For flesh tones on critical catalog pages we found the "oval" shaped dot pattern to work the best and when a second or "touch plate" had to be created the frist color was usually on the Yellow angle (90?) or 15? off the black.

If you have the ability to play with multiple angles I suggest trying the 15? approach, placing the 5th and 6th colors on the less obtrusive angles.

[Lammy]

we ran a promotional peice in hexachrome for ourselves. We ran 200 line and set the green and orange at the magenta and cyan angles as suggested. The peice looked fine. The only thing I can think is to make sure there is not a lot of interaction between the greeen and cyan as well as the magenta and orange in you image. We must have lucked out that they didn't combine and moir

[TigerPress]

Originally Posted by jmiami

We've printed a pantone hexachrome test sheet yet only the PMS spot colors come out correct, the photos are not so good. -

Hexachrome (like any other 'HI-FI' combo) extends the color gamut by adding colors where the CMYK space has shortfalls. Photos only look better if they happen to have colors in this shortfall area. The vast majority of photos do not benefit much from HI-FI color unless they are 'enhanced' usually with lots of saturation.

Originally Posted by jmiami

The potential moir? problem is even worse in the case of "hi-fi" colour where instead of the traditional four CMYK plates there can be up to eight plates. The most common example of hi-fi colour is Pantone's Hexachrome which as its name suggests uses six colours, with additional green and orange plates set on the same angles as magenta and cyan. If any plate is even 1? out of registration your high quality print-run can be ruined. (in Quark the default output is correct in regards to that)

Using the Hexachrome software and the screen angles specified by Pantone, you will not get a significant moir? problem. This is because any specific area of a photo will never contain all six colors. You can see this by viewing the seps in Photoshop.

Of course stochastic screening will also eliminate this problem.

...Wayne

[jmiami]

Thanks for all your input on this question I have about the output. ; )

now for something totally different to break up the day



Vampire octapus/squid
wild right?