# Modifying default magnification of Documentation

Well, finally, after decades of Mathematica rendering notebooks incorrectly in Windows, and after many years of Mathematica not supporting high-resolution displays in Windows, finally version 12.1 fixes these problems. Well, almost

Here's the fly in the ointment: Now the fonts chosen in the documentation are too big: They're using 15-point fonts for default text, which is ridiculously large. This is probably because in the bad old days, before 12.1, Mathematica would render fonts too small (by a factor of 72/96), so the good folks at Wolfram simply upped the font size to make the documentation readable. Which means that now, with fonts suddenly rendered correctly, that size is too large. So, how to fix this?

The easiest solution I can see (short of waiting another 25 years for Wolfram to get those damn font sizes right…) would be to have Mathematica render all of the documentation at a magnification of 0.75, say. So here is my question:

Is it possible to force Mathematica to display all of the notebooks for its documentation at a 0.75 magnification? I figured out that those notebooks use the style sheet "Reference.nb" which I could edit, in principle (after copying it into my user folder hierarchy). I'm just not sure if it is possible to define the magnification of a notebook as a whole in its style sheet, and if so how to do it. I could of course change the magnification for each of the various kinds of cells that are described in Reference.nb, but that's a ton of work, and who knows what I might break by doing so.

Can this be done?

I guess what I am looking for is a statement along the lines of

Cell[StyleData[All], Magnification->0.75]


to be inserted into "Reference.nb" which would cause all content using that style sheet to be displayed at the specified magnification. I tried that, and was almost successful with it, but now the formatting of the initial documentation page (the one with the pretty colored boxes does not work any more, with text cut off and such.

Quick update: After realizing that, unsurprisingly, all style sheets distributed with Mathematica 12.1 use ridiculously large font sizes (standard text is 15pt), I have sent Wolfram my feedback asking them to fix the issue. I won't hold my breath, though; given the history of this issue I expect a fix to appear on a timescale of decades…

• go to Preferences/Interface/Global Magnification (on the top)
– rmw
Mar 22, 2020 at 9:56
• That’s not a viable solution since it will change the magnification of all notebooks. We need a way to only change it for Mathematica’s documentation.
– Pirx
Mar 22, 2020 at 14:02
• The following code SetOptions[InputNotebook[], Magnification -> 0.75], when executed, changes the magnification of the current notebook to 0.75 (1 is the default). Maybe you can try to execute this code for documentation notebooks only? Mar 22, 2020 at 17:26
• Another idea is to look at what code is being executed when "F1" is pressed, and inject SetOptions there. Mar 22, 2020 at 17:36
• Funny, I'd like them at 125% by default! Mar 23, 2020 at 2:54

• Have you tried changing the Reference.nb style definitions? Mar 23, 2020 at 3:15
• @Pirx all of these styles can be adjusted with style definitions. You're right that the toolbar is semi-dynamically generated (it can be queried from FrontEndResource["FEExpressions", "HelpViewerToolbar"]) but the InputField explicitly inherits from "ControlStyle" and so you can modify it there. You can also shrink the entire bar by setting the Magnification for the "DockedCell" style and there are a number of the InputFieldBoxOptions that may be set in "DockedCell" as well to control that. It's all doable, the only question is how much the large font size bothers you. Apr 26, 2021 at 5:27