How to set linescreen on halftones?

A few thoughts:

(1) Sorry to hear that you are stuck in a workflow that was prevalent in the 1960s through the 1980s. There are few places in the world that still use process cameras to produce negatives that are stripped to make plates.

(2) Modern layout programs typically do not propagate screen settings that may be set in images to the output PDF and PostScript.

(3) Most imagesetters used to create plates (and previously, film) routinely are set to by default ignore any screen settings in the PDF or PostScript input to them. Screen settings are normally set by the operator of the imagesetter globally based on the printing conditions and the device resolution.

(4) Most PostScript laser printers have ignored input stream screen settings for quite a few years now. Some printers do have a setting that allows honoring of such settings, but that is not that common. Furthermore, most applications and drivers provide no means to put that into PostScript anyway! Some such printers do allow setting of a limited number of screen choices from their front panels.

(5) The printer you refer to, the Xerox Phaser 6130N, is a very low end, inexpensive composite color device designed for light use producing color output. It was certainly not designed to produce "camera ready" (long time since I used that term) output for process cameras. As far as I can determine, you cannot change the screening used by this device either via the PostScript or the front panel. This is true for many devices of this class. And for 99.9999% of the users of this class device, such a feature is totally irrelevant.

(6) If you really need to control screening, there are monochrome Adobe PostScript devices from Xante that do allow significant control over the screening both via the input screen and the operator panel.

Quite frankly, your least expensive solution may be to find another printer. If your printer is still stuck with use of process cameras and no support for electronic platemaking, it does not portend well for that printer's survival. Even most Third World printers that I know and/or hear about are well beyond "camera ready" only workflows.

- Dov

I probably should add I use Mac OS X 10.5.6

I managed to open the Xerox PPD with Textedit. Changed halftone screen frequency from 141 to 65, but my halftones still remain too fine to reproduce well. The words "halftone" and "screens" occur a number of places in the PPD but I don't understand what's going on.

Here's the text of the Xerox Phaser PPD:

*PPD-Adobe: "4.3"
*% Adobe Systems PostScript(R) Printer Description File
*% Copyright 1987-1996 Adobe Systems Incorporated.
*% All Rights Reserved.
*% Permission is granted for redistribution of this file as
*% long as this copyright notice is intact and the contents
*% of the file is not altered in any way from its original form.
*% End of Copyright statement
*FileVersion: "1.0"
*FormatVersion: "4.3"
*LanguageEncoding: UTF-8
*LanguageVersion: English
*Manufacturer: "Xerox"
*PCFileName: "XRX6130N.PPD"
*Product: "(Phaser 6130N)"
*PSVersion: "(3015.103) 1"
*ShortNickName: "Xerox Phaser 6130N"
*ModelName: "Xerox Phaser 6130N"
*NickName: "Xerox Phaser 6130N"
*cupsVersion: 1.1
*cupsManualCopies: False
*APPrinterIconPath: "/Library/Printers/Xerox/Icons/Xerox Phaser 6130N.icns"
*cupsFilter: "application/vnd.cups-postscript 0 /Library/Printers/Xerox/filter/XeroxSecureFilter"
*APDialogExtension: "/Library/Printers/Xerox/PDEs/XeroxSecurePrint.plugin"
*APDialogExtension: "/Library/Printers/Xerox/PDEs/XeroxJobAccount.plugin"
*XRPrinterLanguageEncoding: "UTF-8"
*XRPTUserIDScope: "32, 126"
*XRPTUserIDScope: "160, 255"
*XRPTUserIDLimit: "Char, 1, 8"
*XRPTPasswdScope: "48, 57"
*XRPTPasswdLimit: "Char, 1, 12"
*XRPTDocNameScope: "32, 126"
*XRPTDocNameScope: "160, 255"
*XRPTDocNameLimit: "Char, 0, 12"
*XRJALoginIDScope: "32, 126"
*XRJALoginIDLimit: "Char, 1, 32"
*XRJAUserIDScope: "32, 126"
*XRJAUserIDLimit: "Char, 1, 32"
*XRJAPasswdScope: "32, 126"
*XRJAPasswdLimit: "Char, 4, 12"
*XRJADocNameLimit: "Char, 0, 32"
*XRJAHostNameLimit: "Char, 0, 32"
*XRJADateStringLimit: "Char, 0, 32"
*XRJATimeStringLimit: "Char, 0, 32"
*XRJAUsePassword:

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*OpenGroup: InstallableOptions/Options Installed
*OpenUI *InstalledMemory/Memory: PickOne
*DefaultInstalledMemory: 128Meg
*InstalledMemory 128Meg/Standard 128MB: ""
*InstalledMemory 384Meg/384MB: ""
*InstalledMemory 640Meg/640MB: ""
*InstalledMemory 1152Meg/1152MB: ""
*?InstalledMemory: "
save
(Unknown) currentsystemparams /RamSize get
dup 134217728 eq{exch pop (128Meg) exch}if
dup 402653184 eq{exch pop (384Meg) exch}if
dup 671088640 eq{exch pop (640Meg) exch}if
dup 1207959552 eq{exch pop (1152Meg) exch}if
pop = flush
restore
"
*End
*CloseUI: *InstalledMemory

*OpenUI *Option2/RAM Disk: Boolean
*DefaultOption2: False
*Option2 False/Not Available: ""
*Option2 True/Available: ""
*?Option2: "
save
/FXProcs /ProcSet resourcestatus {
pop pop /FXProcs /ProcSet findresource /currentstorage get exec
{(True)}{(False)} ifelse
} {(Unknown)} ifelse = flush
restore
"
*End
*CloseUI: *Option2

*CloseGroup: InstallableOptions

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*UIConstraints: *Collate True *Option2 False

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