+<p>I recommend checking the PNG file in a graphics program like <tt>eog</tt> before using it. Note that the font files should have an alpha layer, which many graphics programs display as a gray-and-white checkered background.</p>
+
+<p>If you're not using Linux, or if you want to use some other method of
+generating fonts, you can do so. The font files must be in PNG format (the
+BMP format doesn't support an alpha layer, which is required for proper
+transparency). They must contain glyphs for the 95 characters between ASCII
+32 (space) and ASCII 126 (tilde, ~), inclusive, plus a 96th glyph that
+rEFInd displays for out-of-range characters. To work properly, the
+characters must be evenly spaced and the PNG image area must be a multiple
+of 96 pixels wide, with divisions at appropriate points. In theory, you
+should be able to take a screen shot of a program displaying the relevant
+characters and then crop it to suit your needs. In practice, this is likely
+to be tedious.</p>
+
+<a name="known_themes">