Prepress Defined

Part of our series where we seek to uncover unfamiliar terms in the world of print.

Prepress describes everything that happens before a project is printed and finished. Before the advent of modern technology, it took up to two weeks to complete the prepress process! Can you imagine that?

Prepress used to mean:

  • Typesetting and pasting onto a mechanical boards.
  • Shooting in camera to make a negative.
  • Opaquing the negatives to remove pin holes in film.
  • Shooting halftones on camera for black-and-white photographs.
  • Creating 4 separate pieces of film for CMYK – if color adjustments were made, this required dot etching.
  • Proofing (one method was called “matchprints”) to make sure the color was exactly what the client wanted.
  • Assembling film onto masks (this was called “stripping”).


Now that we have modern computers, prepress simply means:

  • Computer-to-plate (see below).
And that’s it. What once took days now takes mere hours. All the work that needed to be done to prepare a project for printing can now be done with a couple clicks of a mouse. As long as the files are properly composed for the press, they are simply sent via computer, right to the plate.

Whether you’re new to print and unfamiliar with the ins and outs of the print process or just want to test your own knowledge as a print expert, let’s take a couple minutes to break everything down and define some terms you are going to run into in the print world.

Modern Prepress Terms to Know

  • 4 Color Process (CMYK): The four main primary colors (cyan, magenta, yellow, and key/black) combine to form a full-color image. Every color that comes out on the final copy is a combination of these four colors.
  • Computer-To-Plate: Also known as direct-to-plate, this new technology reduces the printing press to one step – sending files right from the computer to the printing plate.
    Design: The layout of a piece, including copy and photography. This is often done in Adobe InDesign, Adobe Photoshop, and QuarkXPress.
  • Digital Proofing: Proofing is done to show what a printed piece is going to look like. This ensures that the printed job has been set up correctly and will print the way it is intended to.
  • Hardproof: A physical copy of a proof.
  • Printing Plate: A very thin piece of sheet metal that an image is transferred onto. Ink is rolled onto the plate and later transferred to the paper.
  • Softproof: A non-physical copy of a proof.

Legacy Prepress Terms to Know

While these processes have in most cases been updated to more modern technology, you may still come across some of these terms as well:
  • Blueline: Also known as brownline, blues, and low-res blues, this term refers to a photo-print that is used as a final proof before printing to check position of images and color breaks (sometimes supplied as color-broken) for each page. Bluelines are similar to digital proofs in that they show text, image placement and general idea of color.
  • Camera Ready: When a document is ready to be printed, it is known as camera ready.
  • Color Correction: When an image is scanned, the colors may need to be adjusted so that they better match the colors in the original image.
  • Color Management: Checking to make sure that the correct color combinations are being used.
  • Color Separation: A process that involves the separation of full-color originals into four printing colors (CMYK) to prepare them for printing.
  • Continuous Tone: This is how photographs are made up. They must often be broken into halftone using dot etching in order to get the photograph to print correctly.
  • Dot Etching: Using chemicals to break continuous tone into halftone.
  • Halftone: The reproduction of a continuous tone image, such as a photograph. An image gets broken into dots using dot etching methods, and recreates the full tone range of a photograph so that it is able to print correctly.
  • Masks: If there is a certain part of an image that should not be printed, a mask is something that is placed over it to block it out.
  • Matchprints: Similar to proofing, this is a process that shows completed work. It uses actual prepress film to match the colors. With the advent of computer-to-plate technologies, this type of proofing is generally more expensive compared with the newer technologies of digital proofing.
  • Mechanical board: This includes the design and layout of copy and images, as well as instructions that are sent to the printer so it knows exactly how to print the piece.
  • Negative RRED: Abbreviation for negative film which is Right Reading Emulsion Down. This type of film is used mostly by printers in the United States and by clients in supplying film to publishing houses and magazines for ad placement.
  • Negative: Film containing an image in which the values of the original are reverse so that the dark areas appear light and vice versa. Rarely seen now that things have gone digital.
  • Opacity: The property of paper which minimizes the “show-through” of printing from the back side or the next sheet.
  • Phototypesetting: A photographic process that puts type onto photographic paper using negatives and chemicals.
  • Preflighting: Making sure that all digital data is present and valid.
  • Press Proof: Also known as a wet proof, this is a test printing of a subject prior to the final production run. Press proofs are generally printed on the paper stock that will be used for the finished project. A few sheets are run as a final check before printing the entire job and may or may not be made on press to show the general color of a project.
  • Stripping: Assembling film onto masks and to create plates.

Top Takeaways on Prepress

  • Modern technology has simplified the process from several complex steps to one simple step.
  • Digital proofs are in – they are the fastest, easiest, and least expensive ways to proof a project.
  • It is much, much easier to prepare a project for printing.

Technology has made the entire prepress process so much easier. Printers are able to get more projects out faster than ever before, which has increased production significantly.

What has been your experience with the prepress process? Are there any other terms you’ve come across that you’d like to share with us, or ask for clarification on? Comment below!

Download our free eGuide: Printing Defined: The Comprehensive Guide to Unfamiliar Terms in the World of Print

About Allison Jensen

Allison Jensen is the Marketing Coordinator for Compu-Mail and Dual Print & Mail. Allison is a millennial who loves all things direct mail. She is a graduate of the marketing program at Niagara University ('15) with a sales and marketing background in the construction and manufacturing world. Allison also has agency experience and is passionate about blogging and social media.
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