Changing Screen Angles in Duotone Images, Part 2

Part 1 explained how screen angles work, this part of the tutorial will explain how to change them in InDesign, QuarkXPress, Photoshop and Illustrator.

I advise you read the first part of this tutorial, so you understand the reason of this ste-by-step tutorial. Wrongly set screen angles and frequency can cause your job to print incorrectly. Most designers won’t need to deal with those settings, as printers will most likely do that themselves, but extra knowledge on this won’t hurt.

You are required to have Adobe Acrobat Professional, Adobe PS or any other driver that will allow you to make PostScript or PDF files. You will not be able to use the built-in Export to PDF option in InDesign or Export Layout as… in QuarkXPress to do what is described in this tutorial. With InDesign and Illustrator you will also have to produce separated files to be able to change screen angles.

Changing Screen Angles in InDesign and Illustrator

InDesign’s Print Window
(enlarged version)

Those two programs are definitely the most straight forward when we talk about changing screen angles. You do almost the same thing with both programs. On the left you can see the screenshot of InDesign’s Print window and you can see Illustrator’s Print window here.

1. Go to File > Print. The Print window will show up. Choose PostScript File, Adobe PDF or whatever other printer allows you to either create PostScript files in the Printer option which is at the top of the window. Note that choosing Adobe PDF will not create a PDF file, it will create a PostScript file also.
2. Click on the Output tab. In the Colour option, choose In-RIP Separations (the most common separations method).
3. As you can see in this screenshot, there are 5 inks–the 4 process colours and 1 spot colour. Click on the spot colour and change screen angle and frequency. If you are not using cyan, you can just use the screen angle and frequency used by cyan, otherwise use the ones for magenta and yellow. If you are using all the colours, it is best to consult with your printer. You will usually need to make sure there is a difference of 30º amongst the screens.
4. Save to PostScript and you are done.
5. Don’t forget to Distill the file to PDF before you send it to your printer.

Note: Once you have chosen to separate your file and you have changed the screen angle of your inks, you can then choose to output your file as a composite. Once you choose Composite CMYK in the Colour option though, you will notice that you are no longer able to edit the screen angles and frequency of your inks. Yet if you choose Separations again you will see that your changes have been recorded. I suspect this means that you are able to create composite files with custom screen angles with InDesign and Illstrator, but I am not totally sure. If you have any information about this, please fill in the comment form below and let me know.

Changing Screen Angles in QuarkXPress

QuarkXPress’ Print Window
(enlarged version)

Unfortunately with QuarkXPress and Photoshop changing screen angles isn’t as straight forward as it is with InDesign and Illustrator, but it can be done easily. To change screen angles with QuarkXPress:

1. Go to File > Print. The Print window will show up on your screen. Click on Printer.
2. The Printer window will come up. Choose a printer that will allow you to either make PDFs or PostScript files as I mentioned at the beginning of this article (see illustration). Click on Print. If you have chosen Adobe PDF, you will be asked where to save your PDF file. Once you specified it, you will not yet create the file until you finished all the steps I am describing. So go ahead, name your file and press OK. QuarkXPress will save it wherever you told it to, once you have done all the needed steps. In the Printer window, click Print. Again, you will only be brought back to the original Print window mentioned in step 1, QuarkXPress will not yet create the file.
3. Now that you are back to the original Print window, click on the Setup tab and choose either Adobe PDF or Generic Colour as your printer description unless otherwise advised by your printer.

Change the screen angles and frequency in QuarkXPress
(enlarged version)
4. Click on the Ouput tab. To change the screen angle of an ink, first select the ink, then click on Angle and choose Other. You will be prompted to enter your custom screen angle. Do the same with the frequency.
5. Press Print and your PDF or PostScript file will be created.

Changing Screen Angles in Photoshop

Photoshop’s Print window
(enlarged version)

Photoshop doesn’t take into consideration which printer you are using or whether you are separating your file. It just lets you change screen angles with no fuss.

1. Go to File > Print with Preview. Check Show More Options. Straight under it, you will see a drop down menu set by default to Colour Management. Click on that menu and choose Output.
2. A new set of options will appear. Click on screen. When the Halftone Screens window shows up, uncheck the Use Printer’s Default Screen option. You can now change the screen angle and frequency of your inks (see illustration).

Summary

Here is how you change screen angles in InDesign, QuarkXPress, Illustrator and Photoshop. Though most printers will do this for you, it is always good to know what screen angles and frequency are, how they can affect the print quality of your jobs and how to deal with them in case nobody else will do that for you.