MathType EPS Color Separations with QuarkXPress

The information in this document applies to:

Issue

EPS files created by MathType 3.x appear on all layers, rather than just the black layer. Other users may have trouble using background colors with MathType EPS files.

Reason

QuarkXPress depends on EPS images to have color information within them in order to do correct color separations. Because MathType 3.x and earlier did not support color, when QuarkXPress does color separations, the EPS equations created using those versions of MathType end up using whatever color the current PostScript pen is set to. The result is that QuarkXPress does not filter the equations out of any layers, and MathType EPS files end up printing in all separation layers.

MathType 4.0 and 5.0 for Windows have color support for both RGB and CMYK models, and if you define black using the CMYK model, it will print only on the black layer.

Solution

This article addresses the following topics:

1. Forcing MathType 3.x to print only on the black layers

2. Using the CMYK model in EPS files in MathType 4.0 and 5.0 for Windows

3. Trapping and punching out

Forcing MathType 3.x to print only on the black layer

MathType 3.x incorporates an option which will cause MathType to write EPS files which print only on the black layer. To invoke this capability:

1. Quit MathType.
2. If you are using Windows, launch NotePad, the text editor included with Windows, and open MathType.ini, which is located in the Windows directory. 
3. If you are using a Mac, launch SimpleText, the text editor included with Mac OS and open the MathType Preferences file in the Preferences folder in your System Folder.

4. Find the section labeled [General], and enter the line, EPSSwitches = 1. 

5. This will cause MathType to insert the PostScript command 0 setgray into EPS files, which will make QuarkXPress place MathType equations only in the black layer.

6. Save this file, and quit your text editor.

Any new EPS files will now only print on the black layer. Any older EPS files will need to be reopened by MathType and resaved.

Using the CMYK model in EPS files in MathType 4.0 and 5.0 for Windows

For the majority of MathType users, their interest will be to define Black according to the CMYK model, for which instructions are provided here.

1. Launch MathType.
2. Under the Format menu, choose Color and then Edit Color Menu… to open the Edit Color Menu dialog.
3. Click on Black to select it.
4. Click the Edit button to open the Edit Color dialog.
5. Under Model, change it from RGB to CMYK.
6. Click OK to close the Edit Color dialog.
7. Click OK to close the Edit Color Menu dialog.

To define other colors using the CMYK model, you can either edit existing colors or create new ones. To make the color that you have chosen your default color in MathType, click the Make Default button. Please note that if you are creating EPS files with multicolored equations, you should make sure that all the colors that you use in equations are defined using the CMYK model.

Trapping and punching out

This section only applies to you if you want a background color behind the equation. The normal way to treat black text is not to have it punch out of the background color, but to have it overprint instead. But since MathType does not contain color information, Quark does not realize that it is in black, so Quark will punch out any background color. If this is undesirable, you currently have two options:

1. Print your color plates separately, and turn off image printing when you print the plate for the background color. This is done in the print dialog by setting the OPI option to "omit Tiff and EPS".
2. Set the equation background color to "none", and place a separate graphics frame over top of it with your background color. With this new graphics frame selected, choose "Show Trap Information" from the View menu. Now set Background trapping to "Overprint", and print color separations as you would normally.

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