Emulated PostScript (was Re: MacOSX-admin Digest, Vol 39, Issue 26)

[Ashley Aitken]

Hi Alex (et al.),

On 02/04/2007, at 10:24 AM, Alex Satrapa wrote:

> On 02/04/2007, at 11:12 , don montalvo wrote:
>
>> you're right, i should have said "pcl (and emulated postscript)".  
>> but how you define "works just fine"? :) i would never recommend  
>> emulation for a design/graphics/prepress environment.
>
> My experience with emulated PostScript printers has been abysmal.  
> They work for simple text documents just beautifully. They work for  
> simple pictures just beautifully. Then you throw something serious  
> like a 60-page PhD thesis (complex layout, photos, line art,  
> charts) and they end up stalling or corrupting the output - some  
> printers choke because the PostScript file is too big (16MB in one  
> case),

I'm not sure stalling (slowing down) or choking (running out of  
memory?) because the PostScript file is too big or too complicated is  
really a problem with the Emulated Postscript?

> others choke up until the point we remove specific pages (or even a  
> single picture).

Failing to print (choking?) valid postscript or printing the  
postscript incorrectly would most likely be a problem with the  
Emulated Postscript.

My understanding is that there is a PostScript specification defined  
by Adobe.

Adobe also provides an implementation of the PostScript  
specification, which I will call "Adobe PostScript", for their apps  
and printer companies that are prepared to pay (more).

Other vendors provide cheaper implementations of the Postscript  
specification, which are generally called "Emulated  
PostScript" (since there can be more than one implementation from  
different vendors).

Of course, a third party may misunderstand the specification or  
implement it poorly or incorrectly, just as Adobe may (although you  
would hope that Adobe would generally do a better job).

The reality is, I believe, that the "Adobe PostScript" implementation  
used in high-end publishing/printing apps and printers actually  
defines the real complete specification and is the real standard.

As a result, Adobe always wins.  Doesn't mean they are right and the  
others are wrong though.

Cheers,
Ashley.

--
Ashley Aitken
Perth, Western Australia
mrhatken at mac dot com
Skype Name: MrHatken (GMT + 8 Hours!)