Panasonic 8420 Reference Guide

							61 Working with Color
Raster images and vector images
Two broad categories of artwork can be printed from a personal computer 
to a color printer: raster and vector images.
A raster image, also referred to as a bitmap, is composed of a grid of 
pixels, each assigned a particular color value. The grid, when sufficiently 
enlarged, resembles a mosaic made from square tiles. Examples of raster 
images include scans and images created in painting or pixel-editing 
applications, such as Adobe Photoshop and Painter.
The amount of information found in a raster depends on its resolution and 
bit depth. The resolution of a raster describes the density of the pixels and 
is specified in pixels per inch (ppi). The bit depth is the number of bits of 
information assigned to each pixel. Black and white rasters require only one 
bit of information per pixel. For photographic quality color, 24 bits of RGB 
color information are required per pixel, yielding 256 separate levels of red, 
green, and blue. For CMYK images, 32 bits per pixel are required.
When printing raster artwork, the quality of the output depends on the 
resolution of the raster. If the raster’s resolution is too low, individual pixels 
become visible in the printed output as small squares. This effect is 
sometimes called “pixelation”. 
In vector images, picture elements are defined mathematically as lines or 
curves between points—hence the term “vector”. Picture elements can 
have solid, gradient, or patterned color fills. Vector artwork is created in 
illustration and drawing applications such as Adobe Illustrator and 
CorelDRAW. Page layout applications such as QuarkXPress also allow you 
to create simple vector artwork with their drawing tools. PostScript fonts are 
vector-based as well. 
Vector artwork is resolution-independent; it can be scaled to any size 
without danger of pixels becoming visible in printed output.  
						

							Working with Color
62
Optimizing files for processing and printing
The following sections provide tips on how to create image files that 
produce the highest possible print quality while minimizing the processing 
time and disk space they require.
While a 72 ppi raster image appears sharp on a monitor, the same image 
would likely appear pixelated when printed to the KX-P8420. Color print 
devices are capable of much greater detail than monitors, and require 
correspondingly higher resolution image files. However, high-resolution files 
can be large, and therefore cumbersome to transmit over a network, 
process for printing, store on disk, and edit. 
Beyond a certain threshold, a higher image resolution greatly increases file 
size while having a minimal effect on output quality. The optimal image 
resolution depends on the resolution of the final print device. Aim for the 
resolution that optimizes both file size and output quality.
The resolution of a raster, along with its bit depth and physical dimensions, 
determine its file size. The following table shows the file sizes of color raster 
images at different dimensions and resolutions.
In this table, the shaded areas indicate that 200 ppi is typically the best 
trade-off between image quality and file size. However, higher resolutions 
(e.g., 250 to 300 ppi) may be needed for offset printing, when quality is of 
the utmost importance, or for images containing sharp diagonal lines.
Image 
size
File size at
100 ppi150 ppi200 ppi400 ppi
RGB/CMYKRGB/CMYKRGB/CMYKRGB/CMYK
3 x 4 0.4/0.5 MB 0.8/1.0 MB
1.4/1.8 MB 5.5/7.3 MB
5 x 7 1.0/1.3 MB 2.3/3.0 MB
4.0/5.3 MB 16.0/21.4 MB
8.5 x 11 2.7/3.6 MB 6.0/8.0 MB
10.7/14.3 MB 42.8/57.1 MB
Resolution of 
raster images 
						

							63 Working with Color
To find the best image resolution for your purposes, make test prints of 
some raster artwork at different resolutions. Start with a high-resolution 
image (400 ppi) and save versions at progressively lower resolutions, down 
to 100 ppi, using a pixel-editing application such as Photoshop. Always 
save a copy of the original high-resolution version in case you need to 
revert to it. The high-resolution data cannot be recreated from a lower 
resolution version. 
Print the files and examine the output. You will likely begin to see a marked 
deterioration in output quality at resolutions below 200 ppi, while above 200 
ppi the improvement may be very subtle. 
Raster images prepared for offset printing may need to be at higher 
resolutions than needed for proofing on your KX-P8420. 
Ideally, each raster image should be saved at the 
actual size it will be 
placed into the document and at the 
optimal resolution for the print device. If 
the image resolution is correct for the print device, there is no quality 
advantage to be gained by scaling an image down to a percentage of its 
actual size. If you scale a large image down to a percentage of its actual 
size, you incur unnecessary file transfer time because the image data for 
the entire large image is sent to the printer. If an image is placed multiple 
times at a markedly different sizes in a document, save a separate version 
of the image at the correct size for each placement.
If you need to place an image at greater than 100% in a document, 
remember that the output image resolution is affected. For example, if you 
scale a 200 ppi image to 200%, the image is printed at 100 ppi.
100 ppi 200 ppi 300 ppi 400 ppi
Image quality
Image resolution
Scaling  
						

							Working with Color
64
Color management on the KX-P8420
The KX-P8420 uses a simple and flexible color architecture that produces 
excellent color results with default settings. It also allows you to customize 
your color results using various color controls.
Settings for the following KX-P8420 options can be specified via print dialog 
box options when you send a job. Some can also be set as defaults by the 
administrator during KX-P8420 Setup. Settings specified via the print dialog 
box override any equivalent settings at the printer’s front panel.
Explanations of how these settings affect your print jobs are provided in the 
following sections.
Color print optionWhat it does
RGB Source
EFIRGB/sRGB (PC)/
Apple Standard/Off 
(Default: EFIRGB) Applies an RGB source space definition 
to RGB data. 
CRD/Color CRD Text/
Color CRD 
Graphics (Illustrations)/
Color CRD Images (Photos)
Photographic/Presentation/
Transparency
(Default: 
Photographs—Photographic
Text—Presentation
Illustrations—Presentation)Applies a KX-P8420 color rendering 
dictionary (CRD) to objects (text, 
photographs and illustrations) in an RGB 
data file (see page 66). 
With Windows 95, the ColorWise 
Business Color setting assigns default 
CRDs automatically.
For information on how various CRDs are 
used for different types of elements in 
documents, see pages 16,18 (Windows) 
and page 29 (Macintosh).
Brightness 
85% to 115%
(Default: 100%)Performs a color adjustment on all color 
channels to make the printed output 
lighter or darker.
CMYK Simulation
SWOP-Coated/DIC/
Euroscale/None
(Default: None)Adjusts CMYK color data to simulate an 
offset press standard or a custom color 
gamut defined at your site. Selecting 
None bypasses simulation. 
ICM profiles Allows closer color matching between 
monitor and printed output. Click the 
option button to select a color matching 
method, and specify a rendering intent. 
						

							65 Working with Color
The RGB Source option is used to provide a source color space definition 
for RGB data in your document. The setting you specify for this option 
overrides any source color space profiles you may have specified using 
other color management systems. For example, if you specified a 
ColorSync System Profile on the Macintosh computer, the RGB Source 
setting specified in the Print dialog box overrides it. In cases where you 
don’t want this setting to override another specified source color space, 
select Off.
PostScript RGB data is converted to CMYK data using the CRD specified 
by the CRD option (see page 66). This type of RGB data contains its own 
source color space information which is used as a reference point for the 
conversion.
NonPostScript RGB data is converted using a general under-color-removal 
conversion method. NonPostScript RGB data does not contain source color 
space information and so cannot be converted using a CRD.
RGB SourceDescription
EFIRGBThe source color space defined by this setting is 
optimal for color conversions that will be sent to a 
KX-P8420 print device. It also allows for consistent 
output across different operating systems. 
sRGB (PC)The sRGB (PC) setting specifies the source space 
of a generic Windows computer monitor.
Apple StandardThe Apple Standard setting specifies the source 
space of all standard Macintosh computer monitors.
RGB Source  
						

							Working with Color
66
Color rendering dictionaries (CRDs) are used to perform color conversions 
on RGB data. The following table describes the CRDs for KX-P8420 
software and provides guidelines on when to use each one. Each color 
rendering style uses a different gamut mapping method, such as 
Photographic or Presentation, designed for a particular kind of color usage. 
NOTE:
•The rendering styles referred to in the table cannot be used when 
specifying a target device profile with a color management system such 
as ColorSync or ICM.
Rendering styleBest used for
Photographic—Preserves tonal relationships in 
images rather than exact colors. This rendering 
style maps out-of-gamut RGB colors to printable 
colors in a way that retains differences in 
lightness. Color accuracy is sacrificed slightly in 
favor of presenting color relationships in the way 
the human eye perceives them. Photographic 
rendering typically gives less saturated output 
when printing out-of-gamut RGB colors than 
Presentation Color rendering does.Continuous tone 
photographs, 
including scans and 
images from stock 
photography CDs
Presentation—Creates bright saturated colors. 
This rendering style does not try to match printed 
colors precisely to displayed colors but instead 
provides vibrant, dense colors. Photographic 
images, however, are treated the same way as by 
the Photographic rendering style. Artwork and graphs 
in presentations 
and continuous 
tone photographs
Transparency— Improves the correspondence 
between monitor colors and printed color on 
transparency paper. Artwork and graphs 
printed on 
transparency paper
Color rendering 
dictionaries  
						

							67 Working with Color
If you are using the KX-P8420 to print proofs for an offset press job or to 
simulate another print device, select the appropriate CMYK Simulation 
setting. The CMYK Simulation setting specifies the offset press standard or 
other color gamut that you want to simulate.
The CMYK Simulation setting you should specify depends on the press 
standard for which the CMYK data was separated. For example, for images 
that were separated for SWOP-Coated paper, select SWOP-Coated as the 
CMYK Simulation setting. Select SWOP-Coated to simulate printing to a 
standard American offset press; Euroscale to simulate a European offset 
press, or DIC to simulate a standard Japanese offset press. For images that 
were separated using a custom separation (such as a device-specific 
separation or a separation produced with an ICC-profile), select None as 
the CMYK Simulation setting
With PostScript applications, you can create colors using any of the color 
models supported by the application. All PostScript applications support the 
CMYK model; some also support the RGB model and other color models 
based on monitor display values. PostScript applications also allow you to 
select named colors using one or more color libraries, such as PANTONE.
The important thing to remember when creating or choosing colors is that 
the displayed versions of those colors may not match KX-P8420 output or 
the output of identically defined colors from other color print devices. For 
this reason, you should use color matching to ensure predictable color 
printing results with the KX-P8420. 
n Color reference files
Two color reference files have been included on the KX-P8420 Driver & 
Utility CD-ROM: a CMYK color reference file, and a PANTONE color 
reference file.
If you install the printer driver using the installer’s typical or compact 
installation options, the CMYK and PANTONE color reference files are 
automatically copied to the KX-P8420 directory on your hard disk. If the 
color reference files have not been installed, insert the KX-P8420 Driver & 
Utility CD-ROM into your CD-ROM drive and use the installer’s custom 
option to select the reference files to copy to disk. You can also navigate to 
the appropriate directory, and manually copy the files to your hard disk. 
CMYK 
Simulation
Choosing 
colors in 
PostScript 
applications 
						

							Working with Color
68
n Using the CMYK color reference page
The CMYK color reference page, included with your KX-P8420 user 
software, let you see how various cyan, magenta, yellow, and black 
combinations look when printed on your print device. Using the CMYK color 
reference pages, you can easily determine the CMYK values to specify to 
obtain the printed colors you want. 
The CMYK color reference file is an 11-page, letter-size PostScript file.
To use the CMYK color reference pages, download the file using a 
downloader utility such as the WebDownloader. (For instructions on using 
the WebDownloader, see “Chapter 4 Managing Print Jobs”.) The printed 
pages display groups of color patches in graduated combinations of yellow, 
magenta, and cyan, and smaller patches that include 25, 50, and 75% 
black. Refer to these pages to pick colors and specify process color values 
in your application. 
n Using the PANTONE color reference pages
The PANTONE color reference pages, included with your KX-P8420 user 
software, lets you determine the nearest CMYK values to match a given 
color in the PANTONE color for coated paper. 
To print the PANTONE reference pages, download the PANTONE file using 
the WebDownloader. (For instructions on using the WebDownloader, see 
“Chapter 4 Managing Print Jobs”.) The printed pages display PANTONE 
color simulation names and numbers. Refer to these pages to see how 
PANTONE colors defined in applications print on the KX-P8420 printer. 
						

							Appendix A69Fonts
The following section lists the built-in fonts included with your KX-P84\
20 
printer. 
NOTE:
• All fonts that are pre-installed on your printer have also been included\
 on 
the KX-P8420 Driver & Utility CD-ROM. For information on how to install \
these fonts on your computer, see “Installing additional software for\
 
Windows users” in the 
Setup Manual or Operating Instructions.
Resident printer fonts
Listed below are the 136 built-in printer fonts on the KX-P8420.
You can print the list of available fonts by printing “PS Font List”\
. See 
“Printing pages from the front panel” in the 
Setup Manual or Operating 
Instructions
. PS Font List includes the CE font of each font which includes 
multi-lingual extension.
For Macintosh computers, install the corresponding screen fonts from the\
 
KX-P8420 Driver & Utility CD-ROM. For instructions, see “Installing 
additional software for Macintosh users” in the
  Setup Manual or Operating 
Instructions.
The KX-P8420 includes 117 Adobe Type 1 fonts:
•AlbertusMT, AlbertusMT-Italic, AlbertusMT-Light
•AntiqueOlive-Roman, AntiqueOlive-Bold, AntiqueOlive-Compact, 
AntiqueOlive-Italic
•AvantGarde-Book, AvantGarde-BookOblique, AvantGarde-Demi, 
AvantGarde-DemiOblique
•Bodoni, Bodoni-Bold, Bodoni-Italic, Bodoni-BoldItalic, Bodoni-Poster, 
Bodoni-PosterCompressed
•Bookman-Demi, Bookman-DemiItalic, Bookman-Light, 
Bookman-LightItalic
•Carta
•Clarendon, Clarendon-Bold, Clarendon-Light
•CooperBlack, CooperBlack-Italic
•Copperplate-ThirtyThreeBC, Copperplate-ThirtyTwoBC
•Coronet
•Courier, Courier-Bold, Courier-Oblique, Courier-BoldOblique
•Eurostile, Eurostile-Bold, Eurostile-ExtendedTwo, 
Eurostile-BoldExtendedTwo
•GillSans, GillSans-Bold, GillSans-Italic, GillSans-BoldItalic, 
GillSans-Condensed, GillSans-BoldCondensed, GillSans-Light, 
GillSans-LightItalic, GillSans-ExtraBold
Adobe Type 1  PostScript fonts 
						

							70 Fonts
•Goudy, Goudy-Bold, Goudy-Italic, Goudy-BoldItalic, Goudy-ExtraBold
•Helvetica, Helvetica-Bold, Helvetica-BoldOblique, Helvetica-Condensed, 
Helvetica-Condensed-Bold, Helvetica-Condensed-BoldObl, 
Helvetica-Condensed-Oblique, Helvetica-Narrow, Helvetica-Narrow-Bold, 
Helvetica-Narrow-BoldOblique, Helvetica-Narrow-Oblique, 
Helvetica-Oblique
•JoannaMT, JoannaMT-Bold, JoannaMT-Italic, JoannaMT-BoldItalic
•LetterGothic, LetterGothic-Bold, LetterGothic-BoldSlanted, 
LetterGothic-Slanted
•LubalinGraph-Book, LubalinGraph-BookOblique, LubalinGraph-Demi, 
LubalinGraph-DemiOblique
•Marigold
•MonaLisa-Recut
•NewCenturySchlbk-Roman, NewCenturySchlbk-Bold, 
NewCenturySchlbk-Italic, NewCenturySchlbk-BoldItalic
•Optima, Optima-Bold, Optima-Italic, Optima-BoldItalic
•Oxford
•Palatino-Roman, Palatino-Bold, Palatino-Italic, Palatino-BoldItalic 
•StempelGaramond-Roman, StempelGaramond-Bold, 
StempelGaramond-Italic, StempelGaramond-BoldItalic
•Symbol
•Tekton
•Times-Roman, Times-Bold, Times-Italic, Times-BoldItalic
•Univers, Univers-Bold, Univers-BoldExt, Univers-BoldExtObl, 
Univers-BoldOblique, Univers-Condensed, Univers-CondensedBold, 
Univers-CondensedBoldOblique, Univers-CondensedOblique, 
Univers-Extended, Univers-ExtendedObl, Univers-Light, 
Univers-LightOblique, Univers-Oblique
•ZapfChancery-MediumItalic
•ZapfDingbats