RIP
- It's not the end ...
In desktop publishing,
RIP raster image processing [verb] or raster
image processor [noun] wiki is the process and the means of turning
vector digital information such as a PostScript file into a high-resolution
raster image. That is, the RIP takes the digital information about
fonts and graphics that describes the appearance of your file and translates
it into an image composed of individual dots that the imaging device (such
as your desktop printer or an imagesetter) can output.
Think of the RIP as a translator
between you and your printer. You give it instructions in the language of
your desktop publishing application and the RIP translates your instructions
into the language of the printer. If a file doesn't RIP properly, it
may be because your language is too complicated for the translator or it misunderstood
your instructions.
You may not have a RIP,
instead relying on the printer driver to communicate between your application
and your desktop printer. In some cases, this works fine. But in keeping with
our language translator analogy, it's like using gestures and facial expressions
to convey complex ideas not very efficient and some thoughts simply
won't be understood. The RIP offers additional features and functions
not found in your standard printer driver.
Who has the
RIP?
The RIP can be firmware, hardware, or software. Firmware RIP
is built-in to the device, such as the PostScript RIP built-in to many desktop
printers. The hardware RIP is a dedicated piece of hardware configured
to process digital files. It often comes with specific types of devices, such
as an imagesetter. The software RIP is an independent program that
can work with many types of devices.
For basic desktop printing, your
main concern is in having a PostScript capable printer if you'll be printing
EPS graphics and the complex documents common in desktop publishing. Many
laser printers come with PostScript Level 3 RIP. With inkjet printers,
you will have to purchase a separate software RIP solution to get PostScript
unless you're using the more expensive high-end inkjet or dye-sub proofers
that come with PostScript RIP software or hardware.
Large design offices and print
service providers will be the ones with the fancy RIP. In some cases
these RIP solutions can perform additional functions alone or in conjunction
with dedicated software including queuing print jobs, batch processing, imposition,
trapping, color separations, and halftone screening. Some preflight functions
may also be included in the RIP software such as checking for missing fonts
or graphics prior to RIPping.
It Won't RIP
Raster image processing can fail for many reasons. Large file sizes can slow
down the processing. Insufficient memory can keep large files from printing.
Corrupt fonts and graphics, errors in the PostScript code, and other corrupted
data can cause the RIP to fail. An incompatibility between the applications
you are using and the RIP hardware or software can keep error-free
files from printing.
To avoid problems before they happen:
- Keep file sizes manageable.
Crop images in a graphics program rather than in your page layout program
(because even if cropped, the entire graphics file becomes a part of the
document, unncessarily increasing file size and processing time).
- Simplify your document. Avoid
complex blends and nested graphic images.
- Don't mix Type 1 and TrueType
fonts in the same document.
- If using TrueType fonts, check
with your service provider to ensure that they can probably handle them.
Some service providers may be using applications that can't rasterize TrueType
fonts for printing.
- Use the preflight tools in your
page layout application or dedicated preflight software on all your files
to catch common problems before they reach the RIP stage.
- When sending PostScript files
for printing, always print them to your own PostScript printer first. If
you have problems, it's likely that your service provider will as well.
- When preparing PDF files for
high resolution printing, use Acrobat Distiller, not PDFWriter.
- Ascertain what level of PostScript
your service provider is using. If you are creating a PostScript or PDF
file that utilizes features that their PostScript level doesn't support,
problems can occur.
(For example, under certain conditions a PostScript Level 2 RIP will not
correctly separate certain types of duotone EPS files or colorized TIFFs.)
Fix the RIP
Errors that cause the RIP to fail can be easy or difficult to track
down and correct. Here are a few steps you can take, in no particular order:
- If you are getting PostScript
errors, see if the error message and a possible cause are listed in one
of these lists:
- Solving PostScript Errors
- PostScript error messages
- Troubleshooting PostScript Errors
A good webpage about Postscript & the issues just listed above can be
found here or
here (off this site - created
by Laurens Leurs).
Correct the cause and try
printing again.
- Fonts are a frequent culprit.
Change all the fonts in the document to one that you know works. If no errors
occur, replace each font one at a time to find the offending one. Replace
the bad font with something else or with a new, uncorrupted copy of that
font.
- Contact your printer manufacturer
or software publisher to see if there are known issues that may be causing
the errors you are getting.
- Reboot the computer and try
printing again.
- Try printing to another PostScript
printer. If the same errors occur, the problem is probably in the file itself,
not the RIP or the printer. If the errors don't occur, the problem
could still be in the file but it could also be due to a problem with the
RIP and the original printer.
- Print only a page or two at
a time. The job may be too large for the RIP to handle or elements
on a specific page may be causing a problem. When you encounter a page that
won't print, troubleshoot it for font or graphics problems by deleting elements
one at a time.
- Some graphics programs are capable
of creating extremely complex effects with gradients, transparency, and
blends that refuse to print. If you must use these effects, you can try
converting the image to a bitmap format first before placing in your application
file.
- Use Acrobat Distiller to generate
a PDF from your PostScript file. See if you get the same errors.
- Open the file in another version
of the application, save it and try printing again.
- Copy the contents of the file
to a new document, save and try again.
- Open your graphics in their
original application, save in a different format then place them in a copy
of the original document. Try printing it.
- Some programs produce inexplicable
errors even with the simplest files. If all else fails, you may have to
totally recreate your file in a different application. Hopefully you won't
have that experience often, if ever.
This excellent
article was written by Jacci
Howard Bear. The original article can be found here.
Used with Permission.