I'm afraid this is an area where i won't be able to help. I use adobe photoshop to output to a postscript printer. Postscript uses "adobe screening", which is a slightly different than traditional angles and frequency. While i'm asking for 55 lpi, the actual screens vary with the color. The actually values are also based on the DPI of the printer.
I just checked the screen angles and line frequency in Photoshop's print dialog box, and you're right, they're different. Have you had any problems with moiré using the Adobe default settings?
When I break work with each channel separately, convert to grayscale, bitmap then save each separately, the print dialog does not come into play. The default in the bitmap dialog is 50lpi and 45 degrees and it will apply those setting to each color unless you change them.
When printing separations in corel, it assigns a different angle to each color in the print dialog. I don't see anything like that in PS CS2.
I just checked the screen angles and line frequency in Photoshop's print dialog box, and you're right, they're different. Have you had any problems with moiré using the Adobe default settings?
Traditional screens were based on using a mesh similar to screen printing and rotating the fixed mesh around to various angles.When adobe developed postscript, they recognized it was impossible to rotate the angle and not run into math problems when it was applied the cell pattern over top of pixel raster device.
When printing separations in corel, it assigns a different angle to each color in the print dialog. I don't see anything like that in PS CS2.
In photoshop, print with preview (control-alt-p)
Under the preview window is a little pop up menu showing either "output" or "color management"
Select "color management", then under the "Options", "color management" select separations.
Next select "output", then click on screens. When the screens dialog pops up, clock auto and in the next pop up dialog type the respolution of the printer and 55 under the screen.
What would you guys recommend for angle and dot shape for the CMYK layers. Working with each channel in PS worked, but I think I get a better quality halftone in X3 then printing in Ghostscript. I used an output resolution of 800dpi and the "halftone screen" method. I may not be using the proper angles, shape and lpi settings.
55 manual -65 auto lpi
Scott F of usscreen suggests for angles
C-15
M-47
Y-75
K- 75
or
C-22.5
M-52.5
Y-82.5
K- 82.5
Everyone has their magic numbers that work well for their setup.
Your best bet is to try sample various angles and see which works best for you
Would angle matter if you used a round shape? with ellipse or diamond shapes you can see the angle differences, but it seems that with a round shape, it wouldn't matter.
Would angle matter if you used a round shape? with ellipse or diamond shapes you can see the angle differences, but it seems that with a round shape, it wouldn't matter.
Well, I've got my C8800 postscript driver printing nice halftones with Photoshop, but my blacks may not be heavy enough to block 100%. There is a "transparency" option in the PCL driver but not the PS driver. I set the media type to "transparency" on the printer menu, but I don't think it's making a difference. It might be fine. I haven't burned a screen yet. Doesn't seem as dark as my cheap Brother laser though. Any ideas?
i have a ? for you tpitman. it's been a long time since i have done straight cmyk. Common practice in photoshop is to duplicate your file and leave the original open (image - duplicate) then split your channels. select new action, record your bitmap conversion with a pause on screen angle.
Re: Process screen printing - Photos 
