16 Evaluating color laser printers
• Plain papers vary among brands and the regions in which they are manufactured. Some plain
papers have a preferred print side. You should also take into account storage conditions as
well as how the papers handle toner.
• Temperature and humidity should be kept constant for each printer tested. These factors may
affect toner-media interactions and can have an impact on final print quality.
Print viewing conditions
Ideally, quality should be evaluated under a mix of fluorescent and incandescent lighting. Quality
should not be evaluated too close to windows, as natural light changes dramatically with
variations in weather and the time of day.
In addition, the color of the surrounding can significantly affect quality perception. White
surroundings may call undue attention to the color of the media. Medium or light gray is usually
the best choice for the area surrounding where the sample documents will be evaluated.
Individuals may perceive quality differently. HP suggests that you have several people evaluate
your sample documents, in the same environment, with a consistent light source. Have them vote
on the samples that they like by listing them in order from the best to the worst. Allow each person
to rate the samples independently and then record the results. Also, have each person establish a
cut line for acceptable quality for the end-user environment.
Note This process is referred to as psychometric testing and should be performed on all of the
sample documents that you are using to evaluate text, graphics, and image quality.
Evaluating print quality
When you evaluate the overall quality of an output, avoid magnification. Under magnification,
insignificant differences become huge. However, a detailed inspection is still necessary, and when
doing this, look for the following characteristics:
Text print quality
• Text should be dark, not faded.
• Text should be solid black, without hollow spots.
• Edges should be crisp and smooth, not jagged, or with stair-stepping.
• Portrait and landscape text should have the same print quality.
• Toner should not blur or bleed.
Graphics quality
• Edges of colored shapes and graphics should be well formed and smooth.
• Solid color fills should be uniform.
• There should be no bands across graphics.
• Areas of solid black should not bleed into areas of solid colors.
• Areas of solid toner should not wick into the paper fibers.
Image quality
• Images should be clear and sharp.
• There should be no bands across images.
• There should be no graininess or visibility of dots.
• Skin tones should look natural.
• Images should look natural and realistic.
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