Hello!

I'm using Inkscape to create front panel that are compatible with VCV Rack, which is a platform for building (by writing code in C++) synthsizer software.  Their millimeter to pixel ratio is 2.952756.  What I'm attempting to do is use guides in Inkscape to help me position front panel elements. 

The first thing that I did was change the document properties / ratio to 2.952756:

I have guides on the page, like this:

The location in millimeters is correct.  When I change the guide to show its location in PX, I get 94.22196 px. 

That's 3.7795276 pixels per mm, not 2.952756.  The value that I'm hoping to see is 73.6109.  I'm I doing something wrong?  Is there a separate setting for guide ratios?

Thanks!

The default CSS pixel size is currently 96 per inch in Inkscape.
Changing the factor from 1 (96 per inch) to 1.28 (75 per inch) in units.xml should give you the value you are hoping to see.

Thank you so much, @Aero!

Just a quick follow up on this.  Everything worked as suggested.  There were a few hurdles that I had to overcome:

1. I didn't know the location of units.xml.  After some googling, I found it (on Windows) under C:\Program Files\Inkscape\share\inkscape\ui
2. I didn't know where in the XML to make the change.  But I was able to figure it out.  It was here:

   <unit type="LINEAR" pri="y">
       <name>pixel</name>
       <plural>pixels</plural>
       <abbr>px</abbr>
       <factor>1.28</factor>
       <description>CSS Pixels (75/inch)</description>
   </unit>

    

3. The units.xml file was locked.  In order to edit it, I needed to right click on it, choose Properties, then select the Security tab.  From there, I selected Users from the Group list, clicked on the Edit button, and granted Modify access.

Thanks again!