Re: [PLUG] Postscript/Ghostscript question

[Ben Dugan <bdugan@curdes.com>]

> It's been a while since I played with any of this...  But aren't good
> halftone screens, by definition, device dependent?

Yes, I think that's true.  I wanted to see exageratedly large halftone 
cells on my system as a way of knowing that I'd got the right stuff in 
my file.  Then I'd planned to set the cell size, spot function, etc., to 
reasonable values for the printer.

> I always run over to Don Lancaster's Hardware Guru stuff when I need
> cool PS tricks.  He's got a article about good halftone screens for 300
> & 600 dpi lasers.  As your output resolution goes up, you won't have to
> worry so much about the screen though.  What is your film resolution? 
> Anyway, he has a website up now.  http://www.tinaja.com/post01.asp

I stumbled on Don Lancaster's page two days ago when searching and was 
really impressed with the amount of stuff there on postscript.  I always 
think postscript is really cool, so its fun to see that some other 
people seem to think so, too.

The "film resolution" is 2540 dpi: this is being sent to a print service 
place that uses an imagesetter.  The film produces very high density 
blacks and very low absorbance clears.  These are normally used as 
orginals to expose plates for high volume offset printing.  In my case I 
want the film for use in a gray scale shaft-encoder kind of application.

After starting to get the feeling that the halftones were going to be 
determined by the device, I called the printer and asked him about this. 
  It sounds like the printer will interpret the postscript grays I send 
them and make its own screen or halftones as needed.  So my wanting to 
see the halftones myself is probably just a bad instinct that wasted a 
bunch of time!

> There is a ton of PS stuff there.  I'd forgotten how much.  He used to
> have an article called Guru Grays with some halftone info.  I didn't see
> it in a quick read through though.

I'll look there again.

Thanks very much for your pointers!

Ben


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