What is pre press?
Prepress is the process of preparing digital files for a printing press—making them ready for printing. Commercial printing companies usually have prepress departments that review their clients’ electronic files and make adjustments to them to make them compatible with printing on paper or other substrates.
Some of the typical prepress tasks can be performed by the graphic artist or designer who designed the project, but this isn’t required. Graphic artists usually apply crop marks and convert the color of modes of their photos to anticipate any color shifts, but much of the prepress process is handled by experienced operators at commercial printing companies or reprographic companies using proprietary software programs that are customized to the companies’ specific requirements.
Prepress tasks vary depending on file complexity and printing method. Flight checking now means that operator no longer have to manually check each file, The introduction of PDF virtually guarantees a perfect print job every time providing the designer has followed basic rules. But here is a brief overview of common error in supplied files a prepress operator is looking for.
- Correct size.
- Check that the file has been saved correctly.
- Examine files to anticipate and correct any common problems that could prevent the document from printing as expected.
- Double-check fonts to make sure they are embedded and will print correctly.
- Check for bleed.
- Check the job requires spot colour.
- Make sure graphics are in the right format and convert RGB files to CMYK, the format used for printing full-color documents on a printing press.
- Trapping and knockout. Set the trapping, which is a overlap of certain colors to prevent gaps where the colors touch in a layout.
- Set the imposition of the file—putting pages in the right order for printing. It is common to print four, eight, 16 or even more pages on a single large sheet of paper that is later trimmed and sometimes folded into a single unit.
- Produce color digital or soft proofs as requested.
Traditional prepress tasks
In the past, prepress operators They produced artwork with glue and pasted artwork onto pre printed templates before photographing camera-ready artwork using large cameras creating large bromide or film. Prepress operators made color separations from photos, the images were split, by camera into CMYK operations and these were individually spliced into to the film create CMYK printed images, a very time consuming and skilled job.
Today this part of the job along with film is no longer used. That part of the process has pretty much disappeared. Instead the whole process is computerised and the images are transfer directly to metal plates. These plates fit directly onto the press.
Todays prepress qualities and requirements
Prepress operators today must be able to work with the industry-standard graphic software programs including QuarkXPress and Adobe CC 2017 and Acrobat. To a lesser extent an understanding of Corel Draw, Microsoft Word and any other software that a customer may potentially use, including open source programs. Basically if you can understand it you have a chance to find a solution when there is a problem. This as most things is down to experience.
RipSoftware imposition software is very complicated. It not only requires software knowledge but an understanding of how the whole reprographic and print process works. Producing a 300 page plus document to print on the B1 web press is not for the beginner.
Some prepress operators are color specialists and make subtle adjustments to client photos to enhance their appearance when printed on paper. They have a working knowledge of the printing process and binding requirements and how they affect each printing project. This knowledge is vital when producing high quality print. Even in a small digital print company you will require this level of knowledge.