Ubuntu – How to remove fonts from Ubuntu

Edit: I completely updated this answer after getting some breakthrough advice from a colleague.

Here's what I inserted in /etc/fonts/local.conf (inside the <fontconfig> element):

<!-- Replace Helvetica with Arial -->
<match target="pattern">
    <test qual="any" name="family">
        <string>Helvetica</string>
    </test>
    <edit name="family" mode="assign" binding="strong">
        <string>Arial</string>
    </edit>
</match>    

Similarly for Times -> Times New Roman. (See my full local.conf here.) The key was to use binding="strong" for the <edit> element. (Also, using "assign_replace" mode instead of "assign" causes something similar, except that then it's too aggressive: also Verdana gets replaced with Arial).

Changes in font configurations are effective immediately. Besides testing in Firefox, you can check that it works like this:

$ fc-match helvetica
Arial.ttf: "Arial" "Normal"

If you run into problems, the best help is near: man fonts-conf. (Although even with the documentation, the workings of the font system seemed somewhat complicated or unwieldy to me.) You can also try to "debug" what's really going on using a command like:

FC_DEBUG=4 fc-match helvetica

In addition, FC_DEBUG=1024 fc-match helvetica shows the list of config files that affect the font matching.

I suggest visiting the Microsoft Typography site. This claims to provide detailed information on what fonts ship with which products and how to buy addiitonal copies of fonts if needed. For example, this is a link to the Gill Sans fonts shipped in some Microsoft products. If you have fonts that are listed as provided with a product but have not been installed, perhaps because of the installation options selected, you could then discuss with Microsoft what the terms would be for transferring the required fonts from PCs that have the same software installed and have the desired font(s). Their policy on fonts is:

The fonts are governed by the same restrictions as the products they are supplied with. You are not allowed to copy, redistribute or reverse engineer the font files. For full details see the license agreement supplied with the product.

(Taken from their Font Redistribution FAQ)

You may also want to look at the Microsoft Typography site referenced above and at your installed fonts to check the versions of fonts in addition to whether you have them. A different version of the same font may have differences in font metrics, character shapes or range of characters (glyphs) provided. This can result, for example, in a file produced one PC being openable without error on a PC with a different version of the same font(s) but there may be subtle (or obvious) changes in typography or layout. Layout changes could even result in text being no longer visible (e.g. because a fixed-size text box has overflowed).