6 Color
This chapter describes how to produce the best possible color printing:
●
Using color
●
Managing color
●
Matching colors
ENWW 99
Using color
The HP Color LaserJet 3000, 3600, and 3800 Series printers provide automatic color features that generate excellent color results. Carefully designed and tested color tables provide smooth, accurate color rendition of all printable colors.
The printers also provide sophisticated tools for the experienced professional.
HP ImageREt
HP ImageREt is a technology that provides the best color print quality without having to change printer driver settings or make trade-offs between print quality, performance, and memory. ImageREt produces photorealistic images.
Depending on your printer, the following HP ImageREt versions offer trapping technologies, control over dot placement, and more precise control of the toner quality in a dot.
●
HP ImageREt 2400 (HP Color LaserJet 3000 Series printer) produces a 600x600 dpi print resolution that provides 2400-dpi laser-class quality with millions of smooth colors.
●
HP ImageREt 3600 (HP Color LaserJet 3600 and 3800 Series printers) produces a 600x600 dpi print resolution that provides 3600-dpi laser-class quality with millions of smooth colors.
Media selection
For the best color and image quality, select the appropriate media type from the software printer menu or from the printer control panel. See
Selecting print media
.
Color options
Color options automatically provide optimal color output. These options use object tagging, which provides optimal color and halftone settings for different objects (text, graphics, and photos) on a page.
The printer driver determines which objects appear on a page and uses halftone and color settings that provide the best print quality for each object.
In the Windows environment, the Automatic and Manual color options are on the Color tab in the printer driver.
Standard red-green-blue (sRGB)
Standard red-green-blue (sRGB) is a worldwide color standard that HP and Microsoft developed as a common color language for monitors, input devices (scanners and digital cameras), and output devices
(printers and plotters). It is the default color space used for HP products, Microsoft operating systems, the World Wide Web, and most office software. The sRGB standard represents the typical Windows monitor and is the convergence standard for high-definition television.
NOTE
Factors such as the type of monitor you use and the room lighting can affect the
appearance of colors on your screen. For more information, see Matching colors
.
The latest versions of Adobe PhotoShop ® , CorelDRAW, Microsoft Office, and many other programs use sRGB to communicate color. Because it is the default color space in Microsoft operating systems, sRGB has been adopted broadly. When programs and devices use sRGB to exchange color information, typical users experience greatly improved color matching.
100 Chapter 6 Color ENWW
ENWW
The sRGB standard improves your ability to match colors between the printer, the computer monitor, and other input devices automatically, and eliminates the need to become a color expert.
Printing in four colors (CMYK)
NOTE
This feature is available for the HP Color LaserJet 3000 and 3800 Series printers only.
Cyan, magenta, yellow, and black (CMYK) are the inks that a printing press uses in four-color printing.
Graphic arts (printing and publishing) environments typically use CMYK data files to provide rich, saturated colors for text and graphics. The printer uses the PS printer driver to accept CMYK colors.
CMYK ink-set emulation (PostScript only)
The HP Color LaserJet 3000 and 3800 Series printers use CMYK color rendering to emulate several standard offset-press ink sets:
● Default CMYK+: This selection is good for general-purpose rendering of CMYK data. It is designed to render photographs well while providing rich, saturated colors for text and graphics.
●
Specifications for Web Offset Publications (SWOP): This selection replicates the common ink standard in the U.S. and other locations.
● Euroscale: This selection replicates the common ink standard in Europe and other locations.
●
Dainippon Ink and Chemical (DIC): This selection replicates the common ink standard in Japan and other locations.
● Device: This selection turns off emulation. Color must be managed in the software program or operating system in order to render photographs correctly.
Using color 101
Managing color
Setting color options to Automatic typically produces the best possible print quality for color documents.
However, you sometimes might want to print a color document in grayscale (black and white) or change one of the printer color options.
●
In Windows, use the settings on the Color tab in the printer driver to print in grayscale or change the color options.
●
When using a Macintosh computer, use the Color Matching pop-up menu in the Print dialog box to print in grayscale or change the color options.
Print in Grayscale
Select the Print in Grayscale option from the printer driver to print a color document in black and white.
This option is useful for printing color documents that will be photocopied or faxed.
When Print in Grayscale is selected, the printer uses the monochrome mode, which reduces wear on the color cartridges.
Automatic or manual color adjustment
The Automatic color adjustment option optimizes the neutral-gray color treatment, halftones, and edge enhancements for each element in a document. For more information, see your printer driver online
Help.
NOTE
Automatic is the default setting and is recommended for printing all color documents.
Use the Manual color adjustment option to adjust the neutral-gray color treatment, halftones, and edge enhancements for text, graphics, and photographs. To gain access to the manual color options, from the Color tab, select Manual, and then select Settings.
Manual color options
Use manual color adjustment to adjust the Color (or Color Map) and Halftoning options individually for text, graphics, and photographs.
NOTE
In programs that convert text or graphics to raster images, the Photographs settings also control text and graphics.
Table 6-1
Manual color options
Setting description Setting options
Halftone
Halftone options (available for the HP Color LaserJet
3000 and 3800 Series printers only) affect the color output resolution and clarity.
● Smooth provides better results for large, solid-filled print areas and enhances photographs by smoothing color gradations. Select this option when uniform and smooth area fills are the top priority.
●
Detail is useful for text and graphics that require sharp distinctions among lines or colors, or images that contain a pattern or a high level of detail. Select this option when sharp edges and details are the top priority.
102 Chapter 6 Color ENWW
ENWW
Table 6-1
Manual color options (continued)
Setting description Setting options
Neutral Grays
The Neutral Grays setting (available for the HP Color
LaserJet 3000 and 3800 Series printers only) determines the method for creating gray colors used in text, graphics, and photographs.
●
Black Only generates neutral colors (grays and black) by using only black toner. This guarantees neutral colors without a color cast.
● 4-Color generates neutral colors (grays and black) by combining all four toner colors. This method produces smoother gradients and transitions to other colors, and it produces the darkest black.
Edge Control
HP Color LaserJet 3000 and 3800 Series printers:
The Edge Control setting determines how edges are rendered. Edge control has two components: adaptive halftoning and trapping. Adaptive halftoning increases edge sharpness. Trapping reduces the effect of color-plane misregistration by overlapping the edges of adjacent objects slightly.
● Maximum is the most aggressive trapping setting. Adaptive halftoning is on.
●
Normal is the default trapping setting. Trapping is at a medium level and adaptive halftoning is on.
● Light sets trapping at a minimal level, and adaptive halftoning is on.
●
Off turns off both trapping and adaptive halftoning.
HP Color LaserJet 3600 Series printer:
● Maximum is the most aggressive trapping setting.
●
Normal sets the trapping at a medium level.
●
Light sets trapping at a minimal level.
●
Off is the default trapping setting. Trapping is turned off.
RGB Color (HP Color LaserJet 3000 and 3800 Series printers only)
● Default (sRGB) instructs the printer to interpret RGB color as sRGB. The sRGB standard is the accepted standard of Microsoft and the World Wide Web Consortium ( http://www.w3.org
).
●
Image optimization (sRGB) (HP Color LaserJet 3800 Series printer only) instructs the printer to use the best color matching for rendering sRGB images. Select this option to print raster objects, such as .BMP, .TIF, or .GIF files.
● Adobe RGB (1998) (HP Color LaserJet 3800 Series printer only) instructs the printer to use the best color matching for documents or images that are in the Adobe RGB color space that some digital cameras and high-end graphics programs create. When printing with Adobe RGB from a professional software program, turn off the color management in the program and allow the printer software to manage the color space.
●
None instructs the printer to print RGB data in raw device mode.
You must manage color in the program in which you are working or in the operating system in order to render photographs correctly when this option is selected.
● Custom Profile instructs the printer to use a custom input profile to more accurately predict and control color output. Download custom profiles from www.hp.com
.
Restricting color printing
NOTE
This feature is available for the HP Color LaserJet 3000 and 3800 Series printers only.
Managing color 103
The HP Color LaserJet 3000 and 3800 Series printers include a RESTRICT COLOR USE setting for networked printers. A network administrator can use the setting to restrict user access to the color printing features in order to conserve color toner. If you are unable to print in color, see your network administrator.
1.
Press Menu.
2.
Press to select PRINT QUALITY, and then press .
3.
Press to select SYSTEM SETUP, and then press .
4.
Press to select RESTRICT COLOR USE, and then press .
5.
Press to select one of the following options:
●
DISABLE COLOR: This setting denies the printer color capabilities to all users.
● ENABLE COLOR: This is the default setting, which allows all users to use the printer color capabilities.
●
COLOR IF ALLOWED: This setting allows the network administrator to allow color use for select users. Use the embedded Web server to designate users who can print in color.
6.
Press to save the setting.
The network administrator can monitor color usage for a specific HP Color LaserJet 3000 Series
printer by printing a color usage job log. See Using printer information pages
.
NOTE
For the HP Color LaserJet 3600 Series printer, the network administrator can deny access to color printing through the Driver Management and Control (DMC) program.
104 Chapter 6 Color ENWW
Matching colors
The process of matching printer output color to your computer screen is complex, because printers and computer monitors use different methods of producing color. Monitors display colors by using light pixels that use an RGB (red, green, blue) color process, but printers print colors by using a CMYK (cyan, magenta, yellow, and black) process.
Several factors can influence your ability to match printed colors to those on your monitor:
●
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 programs
●
Printer drivers
●
Computer operating systems
● Monitors
●
Video cards and drivers
●
Operating environment (humidity, for example)
Keep these factors in mind when colors on your screen do not perfectly match your printed colors.
For most users, the best method for matching colors is to print sRGB colors.
Sample book color matching
NOTE
This feature is available for the HP Color LaserJet 3000 and 3800 Series printers only.
The process for matching printer output to preprinted sample books and standard color references is complex. In general, you can obtain a reasonably good match to a sample book if cyan, magenta, yellow, and black inks are used in the sample book. These are usually referred to as process-color sample books.
Some sample books are created from spot colors, which are specially created colorants. Many of these spot colors are outside the printer gamut (color range). Most spot color sample books have companion process sample books that provide CMYK approximations.
Most process sample books have a note about what process standards were used to print the sample book: SWOP, EURO, or DIC. In most cases, for optimal color matching, select the corresponding ink emulation from the printer menu. If you cannot identify the process standard, use SWOP ink emulation.
Printing color samples
To use the color samples, select the color sample that is the closest match to the desired color. Use the sample’s color value in your program to describe the object that you wish to match. Colors can vary depending on paper type and the software program used.
ENWW Matching colors 105
Use the following procedure to print color samples from the printer control panel:
1.
Press Menu .
2.
Press to highlight INFORMATION, and then press .
3.
Press to highlight PRINT CMYK SAMPLES (HP Color LaserJet 3000 and 3800 Series printers only) or PRINT RGB SAMPLES, and then press .
106 Chapter 6 Color ENWW
