The Printing Process

Tip: What is meant by 4-color process printing and the term "CMYK"?
It means that every color which is printed on the paper is made up of a combination of the 4 process colors of printing - cyan, magenta, yellow, and black.

The Printing Process from start to finish using Offset Printing

This is a brief overview of the various steps and their respective contributions to the production process. Click on one of the areas below to learn more about its specific functions and techniques.

The Design Stage

In the Design Stage the following tasks are addressed by the designer:

  • Overall look & feel of the piece

  • Typography

  • Graphics creation

  • Page layout

The following tasks can be done by the designer or by the prepress department of the print shop.

  • Color Trapping

  • Create Printer Spreads

  • Scan Halftones & Line Art

The Prepress Stage

In the Prepress Stage the artwork is taken from its delivered state (either reflective art or digital file) all the way to the press plates.

Here's how: First the artwork is transferred to negative film either by imaging a digital file through an imagesetter, or by shooting reflective artwork with a copy camera. Second, the pages are stripped together into a flat that reflects how the pages will be printed on the press sheet. And, third the flat is then burned onto a metal plate that will wrap around a press cylinder.

Each color will often have its own film and flat. Exceptions may be when very little color is used, and the colors used don't touch each other color at any point. In this case the color will simply be masked off when burning the first plate, and then revealed to burn the next.

The following procedures are performed by either the electronic prepress operator or the stripper:

  • Imagesetting

  • Shooting Camera Ready Art & Halftones

  • Scanning Halftones & Line Art

  • Color Trapping

  • Imposition

  • Film Stripping

  • Plate Making

The Printing Stage

The Printing Stage covers the transfer of an image to paper. Offset lithography is based upon two main principles:

That water and grease do not mix.

The ink is offset from a plate (positive image) to a rubber blanket (negative image) and then to the substrate (as a positive once again).

When a printing plate is made, the printing image is rendered grease-receptive and water-repellent, while the non-printing areas are rendered water-receptive and ink-repellent. On the press, the plate is mounted onto the plate cylinder which, as it rotates, comes in contact with rollers wet with water (or dampening solution) and rollers wet with ink. The dampening solution wets the non-printing areas and prevents the ink from penetrating these areas. The ink wets the image areas, which are transferred to the intermediate blanket cylinder. The paper picks up the image as it passes between the blanket cylinder and the impression cylinder.

While this process involves primarily one machine, there are many areas of concern.

To ensure high quality printing the printer must:

  • Match the ink color specified

  • Control dot gain

  • Minimize paper movement

  • Minimize image distortion or noise such as dust & hickies.

  • Check that the pages back each other correctly.

  • Evaluate halftone quality and attempt to hold the highlight & shadow detail.

The Bindery Stage

The Bindery Stage is when any trimming, folding, perforating, collating, stitching, or gluing is performed as required.

Inkworks performs the trimming and folding in-house, and works closely with an outside bindery on the collating, stitching and gluing.

A typical job such as a 8.5 x 11 newsletter may include:

  • A post press cut

  • A half fold

  • A double parallel fold