5.1 Introduction
Wayne Collins
Learning Objectives
- Explain why raster image processing requires so much data for print imaging
- Compare resolutions required for digital media and print media
- Compare and contrast the positive and negative attributes between using process and spot colours
- Discuss why Pantone colours are more accurate on a printed swatch than on screen.
- List a number of different industry standard spot colour systems
- Describe trapping issues that occur when adjacent colours are imaged independently
- Analyze different imaging technologies for trapping requirements
- Interpret how black ink is to be used in overprint and boost situations
- Define transparency within the context of prepress workflow management
- Differentiate between flattening transparency on the desktop, or at raster image processing
- Describe the most common press sheet imposition styles
- Analyze different binding styles to select the correct imposition required
- Identify opportunities for nesting multiple images to save materials
- Explain the importance of preflight within the context of pre-press workflow
North America’s fifth-largest manufacturing sector is graphic communications technologies. We can become aware of just how huge this industry is by listing all the manufactured images we see in our day. Your list might include the morning paper or magazine you read, the graphic on the side of the bus you ride to work, and the labels on the grocery shelf where you select your evening meal. Increasingly, more of the graphics that are driving that massive industry are produced with computer graphics software on personal computers. Most of the graphics software used to create the images for reproduction is designed to create images for electronic media — primarily the Internet. Computer graphics designers are not aware of, or concerned with, optimizing their designs for the manufacturing process they are driving. This problem is a root cause of less profitability in most sectors of the graphic communications industry. To tackle this problem, we must become aware of all that happens to a computer graphic from the time it leaves the picture created on the computer screen to the image on the label on the package on the grocery shelf, or the photograph on the side of a bus.
We must first distinguish between traditional pre-press technologies and the pre-imaging processes that are relevant in today’s graphic communications industry. Pre-press processes are different from the way we process images for electrophotographic imaging or imaging with an inkjet engine. We must also distinguish between preparing images for a lithographic press and a flexographic press. Electrophotography and inkjet are growing technologies used to produce customized — or individualized — communications materials. Lithography and flexography are used to manufacture mass-produced media products. These four imaging processes are the core imaging technologies that reproduce 90% of the