screen printing > Separations
Ellipse Vrs Dot shape benefit "example attached"
yorkie:
--- Quote from: squeezee on May 06, 2011, 11:09:31 AM ---Have you seen Mike's latest wheeze?
Imagine that you can print from 10-90% quite happily but lose detail after that. Mike has got a trick where the dots are postscript down to 10% and remain at that size so that you can print them. To get a 9% dot he removes some of the dots and progressively to 1%. It doesn't look perfect but it's a really good approximation. It's a sort of stochastic approach to AM dots.
--- End quote ---
That is exactly the sort of thing i was discussing in my latest post.
http://www.norwb.com/index.php?topic=142.msg2263#msg2263
yorkie:
--- Quote from: drdot on May 06, 2011, 10:36:48 AM ---It is my belief, that screen printing on textiles needs its own book.
Please go back and review the not proportional ratio screen i posted. Is that in the book?
--- End quote ---
I think you're missing the point. Both of the references I cited are foundational material to build your skill set. As an example, the post on moire and "strobe effect" would be enlightening as what you describe is, indeed, a form of moire. The discussion in Fink's book on accurate screens, etc, has more to do with moire issues than on processing speed of the computers. Have you read it?
[/quote]
No, i never bought that book. In 1992, i was a member of the adobe developers association. Everything that was anything to the postscript language was documented in the developer mailings, including floppies with containing code.
The term "accurate screens" involves the ability to select a specific angle/frequency, rather than the snap value to the nearest adobe screen angle/frequency. This was 100% computer speed related. The snap values match th memory layout of the ram. 1200 dpi does not divide evenly by 55. Either you divide 1200 by 21 pixels and get 57.14 lpi or 22 pixels and get 54.54 lpi.
--- Quote from: drdot on May 06, 2011, 10:36:48 AM ---Postscript offers almost infinite possibilities on how to create a halftone model depending on the printing method
--- End quote ---
Postscript 3 only implemented the framework for advanced screening, but left it to the manufacturers to implement in the rip. If i'm wrong, you should be able to reproduce a none proportional screen.
--- Quote from: drdot on May 06, 2011, 10:36:48 AM ---For us, the ideal halftone model would be an intelligent mix of FM and AM halftoning based on the rate of change of surface detail over any defined area.
--- End quote ---
For me, I just want to print pretty shirts. My pet peeve is moires. Beyond FM and AM is morphing shape of the spot and the shifting the phase of the spots. Processor intensive isn't much of an issue these days. A 60 meg raster files is trivial on todays computers.
blue moon:
bump!
this is a great post that many of the new members have not seen. I thought it would good to bring it into the spotlight again.
pierre
Navigation
[0] Message Index
[*] Previous page
Go to full version