Math Expressions feture: Is it possible to change black color to 100% black in CMYK mode?

[Nikos Vardakis]

Hello everyone!

The Math Expression feature in InDesign could be of some help writting math equations in InDesign, but I haven't found a way to change its default RGB color to 100% black in CMYK mode.

I have tried editing the Math expression and changing the

mathcolor="#000000" to another color, but the color is converted to RGB.

I tried changing the Fill Color form the Typeface Properties in Math Expression panel, but still nothing. 

No matter what color or method I try to use, when I export it to pdf, it converts it to RGB.

I want to export the whole book to CMYK, with only black/grayscale colors.

I don't want to use the Preflight option in Acrobat to convert all colors to Black/Grayscale.

If the Math Expressions tool does not support CMYk colors, then, I believe, it is useless!!

Any help, would be appreciated!

Thanks!

Nikos

[Abhishek Rao]

Hi @Nikos Vardakis,

Thanks for sharing the details. I am checking this with the product team and will update you here as soon as I have more information.

Appreciate your patience in the meantime.

Looking forward to sharing an update with you soon.

Abhishek

[Nikos Vardakis]

Thank you @Abhishek Rao!

I will be waiting...

[Abhishek Rao]

Hi @Nikos Vardakis,

Thanks for your patience. I checked with the product team, and at present, the Math Expressions feature renders the objects as SVGs, which only support RGB. This is why the color always converts back to RGB even if you set it to 100% black. CMYK support is not available for Math Expressions right now.

The current workaround is to copy the Math Expression into Illustrator, adjust the color to 100% black there, and then bring it back into InDesign, or to apply a Preflight fixup in Acrobat after export to convert it.

Could you also share your use case with me, so I can pass it along to the team? That will help them better understand the need.

Looking forward to your update.

Abhishek

[Nikos Vardakis]

Hi @Abhishek Rao and thank you for your time.

I'm afraid I didn't understand the following:

Could you also share your use case with me, so I can pass it along to the team? That will help them better understand the need.

What exactly you want me to do?

[Abhishek Rao]

Hi @Nikos Vardakis,

Thanks for asking. What I meant is that our product team would like to understand your specific need for converting Math Expressions to CMYK. Sharing a bit about your use case will help the team better evaluate this request and consider it for future improvements.

Looking forward to your input.

Abhishek

[Nikos Vardakis]

Oh, ok, now I understand, thank you!

I work in a publishing house which is specialized in mostly University publications and many other books.

We create most of the books using InDesign. There are many books (Math, Physics etc) where it is required to type complicated equations.

When I saw the Math Expressions feature, I thought that it would be much easier to type those equations, and, after a while, I saw that it is quite easy!

The problem is, when the whole book is in black color, with black and grayscale text, it has to be exported to pdf, using only the black plate of the CMYK color mode.

When I export it to pdf (in order to sent it for printing), those equations are converted to rich black, using all 4 plates of CMYK colours!

After that, I have to find a way for those "rich black" coloured equations, to convert them to 100% black, using only the black plate of CMYK colour mode.

I hope that this helped you.

Thanks again!

[rob day]

Hi @Nikos Vardakis , Another work around might be to convert the SVG math texts to outlines where you should be able to fill with CMYK 0|0|0|100 black.

Converting to outlines can be scripted, so a script should be able to convert to math elements to outline, set the color to black only and export the PDF.

[Nikos Vardakis]

Hi @rob day and thanks for your reply!

I already tried that, but when you have to edit an equation? You have to create it all over again... and then convert it to outlines again... and so on.

I think that the best solution is, when we change the Fill Colour of the equation in Typeface Properties in the Math Expressions panel, we should have the option to pick a CMYK colour, it will remain CMYK when we export the document to pdf.

[rob day]

when we change the Fill Colour of the equation in Typeface Properties in the Math Expressions panel, we should have the option to pick a CMYK colour

I don’t think that’s possible with SVG fonts—SVG is an RGB only format.

but when you have to edit an equation?

I think you would need a script—a script could convert the equations to outlines, export the PDF, then revert. Not all SVG font characters can be converted to outlines, so you would have to check.

[rob day]

Could you also share your use case with me, so I can pass it along to the team? That will help them better understand the need.

Hi @Abhishek Rao , RGB black would cause problems on an offset press—an RGB black would convert to a 4 color CMYK mix when the separations are output. Small text filled with 4 color black would cause registration problems on press.

[davecourtemanche]

Another scenario is that some copiers / digital printers charge different rates for grayscale prints vs CMYK prints. That can add up on a book that is supposed to be black only.

[Gord@APL]

The issue appears to be that Math Expression builds the expression as an SVG, and SVG doesn't support CMYK.

I've played about with this and found that one can copy the Math Expression from InDesign into Illustrator, fix the colour (and remove the extraneous clipping masks) there, then copy the resulting vector back into InDesign... but that feels like a clumsy and time-consuming workaround when creating a large number of expressions.

If there was a way, within InDesign, to expand the SVG into editable vector elements, that would remove the necessity to copy into Illustrator, but it would also remove the ability to easily edit the expression.

[Nikos Vardakis]

Hello Gord@APL!

Yes, I have already tried that one too! The problem is that, if you want to edit an equation, you will have to do it all over again!

For now, I keep an editable copy of each equation outside the document margins, and then place an outlined copy with 100% black colour, inside my text!

I hope an update will have the option to change color mode to CMYK...

[davecourtemanche]

Hi Nikos

Can you export the PDF / convert to destination and use a grayscale preset? That seemed to convert to K only for me.

[Nikos Vardakis]

Hi @davecourtemanche and thank you for your reply!

Exporting the pdf using a grayscale profile worked!

So, I guess, the solution for the grayscale documents, is this, unless there is something else waiting for me when I actually export the whole document! 

Now, another challenge is, if the document is not grayscale, and has CMYK colours in various pages, what happens if I still want to export the black equations, with only black color, and not rich black.

Any suggestions for that?

Thanks again!