HP Color LaserJet 4550 printer family - Software Technical Reference

Readme files
HP Color LaserJet 4550 Software Technical Reference 225
5. Select OK.
***************************************************
4. HINTS AND TROUBLESHOOTING
***************************************************
4.1 IMPROVING COLOR PRINTING
The process of matching printer output color to your monitor is quite complex because printers and computer
monitors use different methods of producing color. Monitors display colors by light pixels using an additive RGB
(red, green, blue) color process, but printers print colors using a subtractive CMYK (cyan, magenta, yellow, and
black) process.
For most users, the best method for matching colors on your screen to your printer is to print sRGB colors. The
HP Color LaserJet 4550 uses ColorSmart II, which uses sRGB and automatically optimizes color output. Several
factors can influence your ability to match printed colors to those on your monitor. These factors include:
• Print media
• Printer colorants (inks or toners for example)
• Printing process (inkjet, press or laser technology for example)
• Overhead lighting
• Personal differences in perception of color
• Software applications
• Printer drivers
• Operating System of Personal Computer
• Monitors
• Video cards and drivers
The HP web site contains a set of images that allow you to print a sampling of the entire RGB printer color space.
This allows you to create a master print showing the colors to expect for each RGB color requested.
4.2 IMPROVING PRINTING SPEED
Apparent printing speed is affected by the size of the file that is transferred to the printer. The file size can be
minimized without losing color quality in several ways.
• Keep images an appropriate size. The amount of data in images often dominates the data sent to the printer.
Images can be resampled to150 to 200 dots per printed inch (sampled at the size of the final output) with no
loss of quality. This is because the halftone line screen lpi (lines per inch) affects the usefulness of the pixels
more than the printer dot size or dpi.
• If the printed size of an image has been reduced within the document without resampling the image, an image
with a very high dpi (dots per printed inch) can result. Resample the image to an appropriate dpi using the
actual printed size for better performance. Some applications have an option to automatically resample
images to a reasonable size before printing.
• Converting a CMYK file to RGB reduces the number of bytes per pixel of an image by three-fourths. The
effectiveness of file compression can change the exact gain, but in general an RGB file will transfer fewer bits
for faster printing. When converting a file to RGB, select the "sRGB" option if it is available.
• Turn off any options in the application that cause it to resample an image to a higher resolution before
sending it to the printer. Some applications have options to resample images to 300 or 600 dpi before