Year 1 and 2 context

In desktop publishing, RIP — raster image processing  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 your language is too complicated for the translator or it misunderstands your instructions the file doesn't rip.

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 are misunderstood. The RIP offers additional features and functions not found in your standard printer driver.

Who has the RIP?
The RIP comes in firmware, hardware, or software versions. 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 printing EPS graphics and the complex documents common in desktop publishing. Many laser printers come with PostScript Level 3 RIP. With inkjet printers, you 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 use a fancy RIP. In some cases these RIP solutions perform additional functions alone or in conjunction with dedicated software including queuing print jobs, batch processing, imposition, trapping, color separations, and halftone screening. The RIP software may include additional preflight functions such as checking for missing fonts or graphics prior to RIPping.

What can go wrong?

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 your applications 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 handle them. Some service providers use older 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, chances are 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 uses. Creating a PostScript or PDF file that utilizes features that their PostScript level doesn't support, sometimes causes problems. (For example, under certain conditions a PostScript Level 2 RIP will not correctly separate certain types of duotone EPS files or colorized TIFFs.)

How to fix the RIP...

• 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 causing the errors.
• Reboot the computer and try printing again.
• Try printing to another PostScript printer. If the same errors occur, the file itself probably contains the error, not the RIP or the printer. If the errors don't occur, the problem could still reside in the file but the RIP and the original printer are also potential culprits.
• 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 create complex effects with gradients, transparency, and blends that refuse to print. If you must use these effects, 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.