Adobe Photoshop CS4 - Manual (Page 503)

496 USING PHOTOSHOP CS4
Printing
Last updated 1/10/2010
Saving and loading duotone settings
Use the Save button in the Duotone Options dialog box to save a set of duotone curves, ink settings, and overprint
colors. Use the Load button to load a set of duotone curves, ink settings, and overprint colors. You can then apply these
settings to other grayscale images.
Photoshop includes several sample sets of duotone, tritone, and quadtone curves. These sets include some commonly
used curves and colors. Use these sets as starting points when you create your own combinations.
View the individual colors of a duotone image
Because duotones are single-channel images, your adjustments to individual printing inks are displayed as part of the
final composite image. In some cases, you may want to view the individual “printing plates” to see how the individual
colors will separate when printed (as you can with CMYK images).
1 After specifying your ink colors, choose Image > Mode > Multichannel.
The image is converted to Multichannel mode, with each channel represented as a spot color channel. The contents of
each spot channel accurately reflect the duotone settings, but the on-screen composite preview may not be as accurate
as the preview in Duotone mode.
Note: If you make any changes to the image in Multichannel mode, you can’t revert to the original duotone state (unless
you can access the duotone state in the History panel). To adjust the distribution of ink and view its effect on the
individual printing plates, make the adjustments in the Duotone Curves dialog box before converting to Multichannel
mode.
2 Select the channel you want to examine in the Channels panel.
3 Choose Edit > Undo Multichannel to revert to Duotone mode.
Printing duotones
When creating duotones, keep in mind that both the order in which the inks are printed and the screen angles you use
have a significant effect on the final output.
Click the Auto button in the Halftone Screen dialog box to set the optimal screen angles and frequencies (choose File >
Print, then choose Output from the pop-up menu and click Screen). Be sure to select Use Accurate Screens in the Auto
Screens dialog box, if you’re printing to a PostScript Level 2 (or higher) printer or an imagesetter equipped with an
Emerald controller.
Note: The recommended screen angles and frequencies for quadtones are based on the assumption that channel 1 is the
darkest ink and channel 4 is the lightest ink.
You do not have to convert duotone images to CMYK to print separations—simply choose Separations from the
Profile pop-up menu in the Color Management section of the Print dialog box (for setting printer options). Converting
to CMYK mode converts any custom colors to their CMYK equivalents.
Exporting duotone images to other applications
To export a duotone image to a page-layout application, you must first save the image in EPS or PDF format.
(However, if the image contains spot channels, convert it to Multichannel mode and save it in DCS 2.0 format.)
Remember to name custom colors using the appropriate suffix so that the importing application can recognize them.
Otherwise, the application may not print the colors correctly, or it may not print the image at all.