In spite of a whole industry dedicated to it, very few people know what prepress is. “Prepress” is used in the printing industry to refer to all of a commercial printer’s activities after they receive an order and corresponding graphics from a client, but before the actual job begins.
When you produce a business card, magazine, or any type of artwork and send it to a printer, the prepress department takes charge of checking it to make sure it’s ready to be printed without any issues, such as color distortions or size-related problems.
Modern prepress and reprographic professionals usually separate their duties into three stages:
Stage 1: Pre-Flighting
The first stage in the prepress process begins right after the graphics file is created and sent to print. During pre-flighting, trained and experienced technicians make sure the file contains all the necessary elements to undergo a successful print run.
For instance, graphics are checked to ensure the images have the proper resolution and format, the Pantone Matching System/CMYK color is set up, all the fonts are included, and all layout elements like crop marks, bleeds, and margins are also arranged.
Often prepress professionals, depending on the software used to create it, will need to convert the original file to a more printing-friendly format, such as PDF.
Put simply, pre-flighting is a crucial step where potential printing issues are caught early in the process. However, the vast majority of prepress technicians won’t find or correct any grammar or spelling mistakes, so it’s recommended that designers and clients run the file through proofreading and other quality control software before sending it to the printer.
Stage 2: Creating a Proof
Once the graphics file is approved in the first stage, it’s ready to move on to the second prepress stage – creating a proof. A proof is a close representation of how the finished work will appear when it gets printed.
In most projects, such as postcards or business cards, proofs are usually created in PDF format. Since PDFs are electronic files, they can be emailed to clients for a quick and speedy approval.
The main purpose of the second stage is to ensure both printer professionals and clients are in complete agreement on what will be the desired outcome. Also, if your project involves any type of finishing operations like folding or binding – like with brochures or books – a physical proof is often created. This helps demonstrate how the final work will be constructed, the order of its pages, where it will be folded, etc.
Stage 3 – Printing Plates (in Case of Offset Prepress)
If the job requires a digital printing press, then the prepress work is basically over. The graphics file is electronically sent directly to the press without the need to create printing plates.
Although modern commercial printing facilities are shifting more and more towards digital printing, many companies still use the same tried-and-true offset method that has been the gold standard in the industry for over a century.
If the project is sent to an offset press, it requires the creation of printing plates the moment it is approved at the second stage. Printing plates are made from plastic, rubber, metal, paper, and other materials. Their main purpose is to properly transfer images to cardboard, paper, or other substances, and this is achieved using photomechanical, photochemical, or laser processes to engrave the image on the printing plate.
At this point, the actual run begins, bringing an end to the prepress process. From there, the printer lets the press do its job, verifying that the quality stays consistent throughout the run, before sending the shipment to the client. Both then and upon receipt, an additional quality control stage, or sampling, is required to ensure the client is being delivered exactly what they asked. Again, digital proofreading software becomes invaluable here, but it’s only a single key component of the prepress process, which, as a whole, sets the stage for a successful print run.