Make Your Fonts Pretty

Make Your Fonts Pretty

Ubuntu configures GNOME and KDE to use some very pretty fonts, but there are some tweaks you can use to make them even nicer.

Most computer users don't even think about fonts. They just expect them to work and assume that text will look the same whether it's viewed onscreen, printed, or sent to another user in a document. However, font management is actually a surprisingly complex task due to the many subtle variations in the ways fonts can be created and used.

Fonts Are Not Created Equal

Fonts can be defined in a number of different ways and have a variety of file formats. Each operating system has its own method of managing and displaying them. Some fonts are designed as bitmaps to be displayed onscreen, while others are in vector format so they can scale up or down and be printed at high resolution. Some come as bundles that include both bitmap and vector formats in the same package, with one used for onscreen display and the other used in printing or to generate files in output formats such as PDF. And some come as families, with several variations such as bold and italic bundled together with the base font, providing much better results than working from a single base font and then applying such variations algorithmically.

Font Management with Defoma

Ubuntu uses Defoma, the " Debian Font Manager," to centralize and simplify font management across all applications. Applications can vary dramatically in how they manage fonts, so when a new font is installed on your computer, it's not always obvious how to tell each application that the font exists and where to find it.

Defoma gets around this problem by allowing applications to register themselves by providing a Defoma configuration script. Then, when a new font is installed, Defoma works through all the configuration scripts and performs whatever action is necessary to enable the font for each application.

The first thing you should do then is make sure that your system is configured to use Defoma to manage fonts. Run:

$ sudo dpkg-reconfigure defoma
            

If Defoma is not currently set to manage fonts, you will be asked if you want to use it; answer Yes.

If your system has ended up in an unclean state with some manually installed fonts or applications that can't see some fonts, you can force Defoma to totally rebuild its configuration. This process rescans all your installed fonts and makes sure all registered applications have been updated to use them:

$ sudo defoma-reconfigure
            

Onscreen Font-Rendering Preferences

Various displays have different characteristics, and what looks good on a CRT doesn't necessarily look good on an LCD. Ubuntu provides a number of font options through SystemFont (see Figure).

GNOME Font Preferences

You can change the default system fonts to suit your preferences, but if you have an LCD, the item to pay attention to is the subpixel smoothing option under Font Rendering. Each pixel in an LCD consists of three subpixels, one each for red, green, and blue. Subpixel smoothing takes the physical layout of the subpixels into account to display fonts as smoothly as possible.

Advanced options (shown in Figure) are accessible through the Details button near the bottom right.

Advanced font preferences

From here, you can specify screen resolution, smoothing, hinting, and subpixel order.

Screen resolution

When the font renderer displays text onscreen, it needs to convert between various units to determine how large the text needs to be. Often font sizes are specified as points, which are units of measure that have been used (rather inconsistently!) for hundreds of years by printers. Nowadays, most people agree on one point being equal to ¹/₇₂nd of an inch, but if you tell your computer to display, for example, 18-point text, it needs to know the resolution of your display so it can figure out how many pixels are equivalent to ¹⁸/₇₂nds (i.e., ¹/₄) of an inch on your particular screen.

Screen resolution is usually expressed as dpi, or dots per inch. To figure out the horizontal and vertical resolution of your screen, measure its width and height and then divide those values into the pixel dimensions set in SystemScreen Resolution. For example, a typical so-called 17-inch LCD will have physical dimensions of about 13.3 inches by 10.75 inches and run at a native resolution of 1280x1024 pixels. That gives a horizontal resolution of 1280 ÷ 13.3 = 96.2 dpi, and a vertical resolution of 1024 ÷ 10.75 = 95.3 dpi. Close enough to call it 96 dpi for both.

By determining the actual physical resolution of your display and setting the correct Resolution value in the Font preferences, you can ensure that when your computer displays a font onscreen at a specific size, it will be scaled to appear at that actual size.

Smoothing

The Smoothing setting actually controls the level of antialiasing to apply when fonts are rendered. Antialiasing can have a dramatic impact on the clarity of fonts, particularly when displayed on an LCD. It smooths out jaggy corners and edges on fine lines by visually filling in gaps using surrounding pixels set to intermediate shades of grey. If you have an LCD, for the best-looking fonts, you should definitely select Subpixel as the Smoothing setting.

Hinting

Because computer screens operate at a much lower resolution than what we are used to seeing with printed material, fonts that are scaled down to a small size can sometimes suffer from effects whereby the shape and position of individual letters don't interact well with the pixel structure of the display itself, producing visible artifacts. For example, two letters next to each other that both have thin vertical lines may happen to fall slightly differently onto the pixel grid of the display, with the result that one line appears fatter than the other. A similar effect can occur with rounded letters, where fine curves may disappear or be inconsistent. Often the relative placement of letters will alter the visual effect of other letters around them. Hinting is the process of making tiny adjustments in the outline-filling process while rendering fonts to compensate for effects that might cause individual characters to appear differently from the way they were designed.

Doing accurate hinting requires more processor power whenever your computer needs to render large quantities of text, but the end result is text that appears smoother, more consistent and easier to read. You can choose from four hinting levels in Font Rendering Details: None, Slight, Medium, and Full. The difference might seem subtle if you're not used to closely examining text and you don't know what to look for, but if you have a relatively modern machine, it's worth turning on hinting. LCDs in particular can benefit greatly from it, giving you much more readable text and less eyestrain.

Subpixel order

In the main Font Preferences dialog, there was an option to turn on subpixel smoothing, but for it to be really effective, you also need to make sure your computer knows the physical structure of the individual subpixels. In reality, subpixels are not dots: they're typically very short lines placed side by side.

The vast majority of LCDs use an RGB order, but some reverse that and place the subpixels in BGR order. Then there are variations on those two options, with some manufacturers stacking subpixels vertically instead of placing them side by side. Selecting the option that matches your particular monitor structure will let your computer do the best job possible of smoothing fonts onscreen.

Install Microsoft Core Fonts

Microsoft Windows comes bundled with a number of core TrueType fonts. Because Windows is so widely used, many documents and web sites are designed around the core Microsoft fonts, and if you don't have them installed, your computer may not be able to display some documents as the author intended. Licence restrictions prevent the Microsoft fonts from being distributed directly as part of Ubuntu, but Microsoft does make them available for free download directly from its web site, and there is even an Ubuntu package that takes care of downloading and installing them for you:

$ sudo apt-get install msttcorefonts
            

The msttcorefonts package is part of the multiverse repository, so it's not available on a standard Ubuntu installation and you may need to "Modify the List of Package Repositories" [Hack #60] before you can install it.

The package doesn't include the fonts themselves but instead connects to the Microsoft web site and downloads and installs them in the correct location on your computer. The fonts will then be available to applications the next time they start up.

Install Macintosh and Windows TrueType Fonts

Installing TrueType fonts is very easy on Ubuntu. On your desktop or in a file-browser window, just type Ctrl-L to access the Open Location window; then type fonts:/// and click Open. You will then see a list of all the fonts you currently have access to on your system. Drag your new TrueType font from your desktop or file manager into the font-list window, and it will be automatically installed and made available to applications through Defoma the next time they start up.

It's actually not quite that simple if the fonts come from a Macintosh system, because Mac OS embeds extra font information using a special format that Linux can't read directly. Before you drag Mac OS fonts into your fonts:/// folder, you need to convert them with a utility called fondu, which you can install with the following command:

$ sudo apt-get install fondu
            

Then copy your Mac OS font directory to your Linux machine and run:

$ fondu *
            

inside it to generate converted TTF files.

The fonts:/// location isn't a real location in the filesystem. It's a virtual view that lets you manage the fonts that have been installed without having to worry about where they are actually located on disk. The fonts shown by default are the system-wide fonts that have been installed on your machine for all users to access, but when you drag a new font into the window, it actually stores it inside a hidden folder called .fonts inside your home directory.