Prepress activities include a wide variety of procedures within the print production process. Prepress procedures begin with the design of a project and conclude with platemaking. Over the years, each of prepress steps have undergone many changes in the way that they are accomplished. 

Before desktop publishing, ideas were sketched on paper, thumbnails were created, and copy was handwritten. The typesetters would set the copy and output galleys of type for the proofreaders to check. After the corrections were made, copy was output with phototypesetters on resin coated (RC) paper. The columns of type were trimmed out, and using an adhesive, either wax, spray mount, or rubber cement, the strips were keylined onto layout boards (mechanicals) by page layout artists (or keyliners). Photo placement was either drawn in with a Rapidograph pen or Rubylith was placed in the position of the photo. Artwork, such as logos, were shot on a camera to create a stat that could be placed on the keyline. Color breaks were made using markers on tissue overlays. The keylines and photos were then shot on a process camera with film, using colored filters and contact halftone screens. The film was then sent to the stripping department, where it was stripped onto a flat, sometimes using imposition. The flat was then used to produce a plate that was placed on a press for printing the job. All of the prepress steps were time consuming and involved several people to complete the work.

Times have changed. Today, a print project is usually designed on a computer and typeset in a page layout program. Color or black and white images are created on a computer using various software programs unless a scanner is used to convert a photograph or artwork into a digital image, which can then be stored on a computer. The images stored on a computer are known as digital bitmap images, and can be color corrected or manipulated in any way. When an image is first being corrected or modified, it is viewed on a calibrated monitor. Viewing an image on a monitor is the first process of proofing and is called soft proofing, or monitor proofing. When the designer is pleased with the image, it is output to film and a scatter proof is made. The scatter proof is then checked for correct color densities in a viewing booth. The layout file (called a LW file meaning linework) and the photos (CT's or Continuous Tones) are merged in the assembling process. From there, the file is sent to a RIP (Raster Image Processor) which translates the digital information into four halftone color separations (cyan, magenta, yellow, and black). The information is sent to either a digital proofer or to an imagesetter for film to be output in order to create an analog proof. After the proof has been approved, the film can then be stripped into flats that are used to generate the plates. In a direct-to-plate workflow, film is eliminated and the digital file is sent from the RIP directly to a platesetter. And, if a digital press is to be used for printing the job, the file can be sent directly to the press, eliminating the need for a plate.