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mindwaves · May 5, 2003, 01:39 AM

Ok, I am not a graphics designer or a page layout person, but I do not see the advantage/uses of Postscript. Can someone please explain it to me? Thanks.

jesperas · May 5, 2003, 01:20 PM

Originally posted by mindwaves:
Ok, I am not a graphics designer or a page layout person, but I do not see the advantage/uses of Postscript. Can someone please explain it to me? Thanks.

Postscript is a page description language, but I'm not sure what you mean by advantages/uses of Postscript? Are you asking about Postscript laser printers, or vector drawing applications like Illustrator, or...?

Quartz in Mac OS X uses PDF as the basis of its imaging model, which in turn is based on Postscript.

andi*pandi · May 5, 2003, 02:30 PM

<imagines world without postscript and mind reels>

fuzzy text, no vector graphics... it'd be 1987 all over again.

keywest · May 5, 2003, 06:30 PM

I am trying to figure out what you mean. Nothing printed would look the same without it. You do realize that don't you? As mentioned above, fuzzy, bitmapped, aaahhhhrggh.

Maybe you could explain a little more what you mean.

mindwaves · May 5, 2003, 10:15 PM

Ok, I think that I sort of understand what it means now. So what is the difference between a postcript printer and a non-postscript one? Thanks.

gadster · May 10, 2003, 12:15 PM

Originally posted by mindwaves:
Ok, I think that I sort of understand what it means now. So what is the difference between a postcript printer and a non-postscript one? Thanks.

As far as I know...

A postscript printer uses the postscript data in the file you are printing to generate the printed page. If you enlarge it 4000% (and tile it) all the vector info will be as sharp as at 100%. Bitmap data may get blurry and pixellated.

Non-postscript printers just print take the screen data and print that. If you blow that up 4000%, EVERTHING will get blurry and pixellated.

It's got to do with postscript using vector info. The file 'says' "I am a rectangle - my short sides are 50% the length of my long sides and my long sides are 45 inches big, I start at 1 inch in, and 1 inch down, and I am colored black."

A non-postscript device work like this -
this pixel is 100% white, this pixel is 100% white, this pixel is 100% white, this pixel is 100% white, this pixel is 10% black, this pixel is 15% black, this pixel is... etc FOR EVERY PIXEL in the image.

Postscript is an efficient page description language that is supposed to be device independant. With postscript you could make an enormous poster with, say, a red background, some colored circles and some type, and the file size could easily be less than 200K (say). To make the same file as a tiff, it could easily get as big as a couple of Gig, and STILL not print as sharp, due to its reliance on pixel by pixel description of the 'page'.

Hope that helps.

mindwaves · May 12, 2003, 01:15 AM

Gadster,

A very, very, informative post. Thank you. I now know what it is used for. haha..very interesting

bluedog · 10:16 AM

There are alternatives to Postscript, but most of them are not used in the professional printing field.

PCL is a 'postscript knockoff' that Hewlett Packard created because they didn't want to pay the licensing fee to Adobe for their 'page specification language' of Postscript. It functions for the same purpose of Postscript and runs on MOST PC printers today.

Postscript is used on many different print devices to figure out how to create the data the printer actually uses to generate the image on your output.

In printing often Postscript is related to a RIP (raster image processor). The postscript is really just a description of how the page should look, the postscript interpreter is a program designed to create the data necessary for the printer (i.e. the dot patterns and colors the printer needs to know how to make the image). A RIP is simply a postscript interpreter, and there are Adobe certified ones and 'compatible' ones made by other companies.

In reality every printer needs some interpretation from what you send it, to how it prints the image. With postscript built-in, the printer handles it automatically. HP printers and others use PCL or you can get the Postscript add-on.

A RIP either in a hardware add-on or through software (likely running on a computer), is an alternative way to get your image to the printer. It translates the postscript information of curves, lines and fills into the maximum resolution of the printer when it is being 'RIPped'. That's the beauty of postscript, it doesn't matter what you send your postscript data to, the interpreter will always make the best of it that the printer is capable of outputting.

Postscript FONTS on the other hand inherit the benefits of postscript, but require an interpreter in the OS to view them on-screen. With XP or MacOSX the interpreter is built-in but prior to that software such as Adobe Type Manager (ATM for short) was necessary to scale the fonts on screen. They have a distinct advantage over TrueType fonts in the quality at all sizes.

Many font foundries can create a professional-looking font with Truetype, but the technology doesn't have a feature called 'hinting' that is available with Postscript type. This hinting allows for the type at really small sizes to get a hint as to changing the form on each letter for better legibility and more consistent appearance. TrueType fonts do not have this, and at small sizes can 'fill-in' lettershapes or become less legible than a properly created Postscript version that takes advantage of hinting.

The average user, with the average printer isn't going to know or notice the difference.

Sorry for the long-winded response, just thought this background info would be useful.