Apparently my last post hit HackerNews and I didn’t know it. That’s what I get for not checking my server logs.

Going through the comments I see that about 30% of people find it interesting and 70% think I’m an idiot. That’s much better than usual, so I'm going to tempt fate with another installment. The general interest in my post (and let’s face it, typography for source code is a pretty obscure topic of discussion), spurred me to write a follow up.

In today’s episode we’ll tour the font themselves. If we want to reinvent computing it’s not enough to grab a typewriter font and call it a day. We have to plan this carefully, and that starts with a good selection of typefaces.

Note that I am not going to use color or boxes or any other visual indicators in this post. Not that they aren’t useful, but today I want to see how far we could get with just font styling: typeface, size, weight, and style (italics, small caps, etc.).

Since I'm formatting symbolic code, data, and comments; I need a range of typefaces that work well together. I’ve chosen the Source Pro family from Adobe. It is open source and freely redistributable, with a full set of weights and italics. More importantly, it has three main faces: a monospace font: Source Code Pro, a serif font: Source Serif Pro, and a sans-serif font: Source Sans Pro. All three are specifically designed to work together and have a range of advanced glyphs and features. We won't use many of these features today but they will be nice to have in the future.

Lets start formatting some code. This will be a gradual process where we chose the basic formatting then build on top for different semantic chunks.

For code itself we will stick with the monospace font: Source Code Pro. I would argue that a fixed width font is not actually essential for code, but that’s an argument for another day when we look at indentation. For today we’ll stick with fixed width.

Code comments and documentation will use Source Serif Pro. Why? Well, comments don’t need the explicit alignment of a monospace font, so definitely not Source Code Pro. Comments are prose. The sans serif font would work okay but for some reason when I think "text" I think of serifs. It feels more like prose. More texty.

So I won’t use Source Sans Pro today but I will save it for future use. Using the Source [x] Pro set gives us that option.

Below is a simple JavaScript function set with the default weights of those two fonts. This is the base style we will work from.


So that’s a good start but.., I can immediately think of a few improvements. Code (at least in C derived languages) has five main elements: comments, keywords, symbols, literals, and miscellaneous — or what I like to call ‘extraneous cruft’. It’s mainly parenthesis and brackets for delimiting functions and procedure bodies. It is possible to design a language which uses ordering to reduce the need for delimiters, or to be rid of them completely with formatting conventions (as I talked about last week). However, today’s job is to just restyle without changing the code so let’s leave them unmolested for now. Instead we will minimize their appearance by setting them in a thin weight. (All text is still in black, though).

Next up is symbols. Symbols the part of a program that the programmer can change. These are arguably the most important part of the program; the parts we spend the most time thinking about, so let’s make them stand out with a very heavy weight: bold 700.


Better, but I don’t like how the string literal blends in to with the rest of the code. String literals are almost like prose so let’s show them in serif type, this time with a bolder weight and shrunk a tiny bit (90% of normal).

For compatibility I did the same with numeric literals. I’m not sure if ‘null’ is really a literal or a symbol, but you can assign values to it so I’ll call it a literal.


Next up is keywords. Keywords are the part of the language that the programmer cannot change. They are strictly defined by the language and completely reserved. Since they are immutable it doesn’t really matter how we render them. I could use a smiley face for the function keyword and the compiler wouldn’t care. It always evaluates to the same thing. However, unlike my 3yr old’s laptop, I don’t have a smiley face key on my computer; so let’s keep the same spelling. I do want to do something unorthodox though. Let’s put the keywords in small caps.

Small caps are glyphs the size of lower case letters, but drawn like the upper case letters. To do small caps right you can’t just put your text in upper case and shrink it down. It would look strange. Small caps are actually different glyphs designed to have a similar (but not identical) width and a shorter height. They are hard to generate programmatically. This is one place where a human has to do the hard work. Fortunately we have small caps at our disposal thanks to the great contributions by Logos and type designer Marc Weymann. Open source is a good thing.


Now we are getting somewhere. Now the code has a dramatically different feel.

There’s one more thing to address: the variables. Are they symbols like function names? Yes, but it feels different than function names. They are also not usually prefixed with a parent object or namespace specifier. Really we have three cases. A fully qualified symbol like ‘baz’ in, the prefix part (, and standalone variables that aren’t qualified at all (like ‘x’). This distinction applies whether or not the symbol is a function or an object reference (it could actually be both in JavaScript).

In the end I decided these cases are related but distinct. Standalone symbols have a weight of 400. Technically this is the default weight in CSS and shouldn’t appear to be ‘bold’, but since the base font is super light, regular will feel heavier against it. The symbol at the end of a qualifier chain will also be bold, but with a weight of 700. Finally the prefix part will be italics to further distinguish it. There really isn’t a right answer here; other combinations would work equally well, so I just played around until I found something that felt right.

This is the final version:


I also shrunk the comments to 80%. Again it just felt right, and serifed fonts are easier to read in longer lines, so the comments can handle the smaller size.

Here’s a link to the live mockup in HTML and CSS. This design turned out much better than I originally thought it would. We can do a lot without color and spacing changes. Now imagine what we could do will our full palette of tools. But that will have to wait for next time.

BTW, if you submit this to Hacker News or Reddit please let me know via Twitter so I can answer questions.

Allow me to present a simple thought experiment. Suppose we didn’t need to store our code as ASCII text on disk. Could we change the way we write -- and more importantly read -- symbolic code? Let’s assume we have a magic code editor which can read, edit, and write anything we can imagine. Furthermore, assume we have a magic compiler which can work with the same. What would the ideal code look like?

Well, first we could get rid of delimiters. Why do we even have them? Our sufficiently stupid compilers.

Delimiters like quotes are there to let the compiler know when a symbol ends and a literal begins. That’s also why variables can’t start with a number; the compiler wouldn’t know if you meant a variable name or a numeric literal. What if we could distinguish between then using typography instead:

Here’s an example.


This example is semantically equivalent to:

print "The cats are hungry."; //no quotes or parens are needed

Rendering the literal inside a special colored box makes it more readable than the plain text version. We live in the 21st century. We have more typographic options than quotes! Let’s use them. A green box is but one simple option.

Let’s take the string literal example further:


Without worrying about delimiting the literals we don’t need extra operators for concatenation; just put them inline. In fact, there becomes no difference between string concatenation and variable interpolation. The only difference is how we choose to render them on screen. Number formatting can be shown inline as well, but visually separate by putting the format control in a gray box.


Also notice that comments are rendered in an entirely different font, and pushed to the side (with complete Unicode support, of course).

Once we’ve gone down the road of showing string literals differently we could do the same with numbers.


Operators are still useful of course, but only when they represent a real mathematical operation. It turns out there is a separate glyph for multiplication, it’s not just an x, but it’s still visually confusing. Maybe a proper dot would be better.

Since some numbers are actually units, this hypothetical language would need separate types for those units. They could be rendered as prose by using common metric abbreviations.


In a sense, a number with units really is a different thing than plain numbers. It’s nice for the programming language to recognize that.

As long as we are going to have special support for numeric and string literals, why not go all the way:

Color literals


Image literals


Byte arrays


If our IDEs really understood the concepts represented in the language then we could write highly visual but still symbolic code. If only our compilers were sufficiently smart.

I’m not saying we should actually code this way but thought experiments are a good way to find new ideas; ideas that we could then apply to our existing programming systems.

Typography is the study of type, meaning letter forms of the printed word; though in modern usage it includes all manner of non-printed letter forms such as computer screens, eBooks, electronic billboards, and even textiles. Typography is possibly the most important part of design because humans are visual creatures and nothing conveys more information in a smaller space than words. This article will cover the basic terms and anatomy of type, then give you some quick tips to help choose fonts wisely. Unlike my last topic, color, modern typography is actually quite old. Most of modern color theory was developed in the 20th century with the invention of modern dyes, paints and emissive displays. The core typographic theories, however, were in place when Gutenberg made the first printed books over 500 years ago. Certainly a lot has been developed since then, but the universal principles of type like alignment and grids were already developed during the dark ages by monks transcribing bibles by hand. When Gutenberg converted these principles to his mechanical printing press modern typography was born.

Typeface vs Font

First things first: typefaces versus fonts. A typeface, also called a font family, is a set of fonts designed with a stylistic unity, each comprising a coordinate set of glyphs. ( A font is a complete character set of a typeface at a particular size, weight, and style. In software engineering terms you can think of a typeface as a class and the font as an instance of that class with a particular configuration. The exact meaning of typeface and font have changed subtly over the years as the technology has shifted from mechanical type to computer-set type to purely digital type. Originally fonts from the same typeface were literally different boxes full of chunks of metal shaping each letter at a given size. These days we have scaleable font technology so different sizes, weights and styles can be generated algorithmically or the multiple forms can distributed in a single physical file. Thus font and typeface have somewhat merged, and today you can safely refer to a typeface as a 'font' in general usage, and only use the more precise terminology when referring to particular instances of that font (or when talking to ornery typographers).

Anatomy of a Font


The weight of a font is the thickness of the lines that make up the letter forms. Since this thickness is relative to the size of the letters we refer to these as their weight. You are probably most familiar with bold vs regular, but some fonts have as many as nine weights from thin and light up to bold, heavy, and black. The True Type font format specifies weights on a scale from 100 to 900. CSS can use words or scale numbers to specify the weight. Police-Helvetica.gif Helvetica (

Style: AKA Slope, Italic & Oblique

We usually think of the slope of a font as italic or normal but, as with everything in typography, there's more subtlety to it. Italic text really means text which is drawn differently to indicate it is emphasized and should stand out in some way. Italic text can be programmatically generated by leaning the text to the right, called oblique text. Some fonts include a true italics form which actually draws the letters with different shapes. Fancier fonts may lower the fs, adjust the roundness of letters, or lean to the left instead of the right (depending on the language). FirefoxScreenSnapz016.png FirefoxScreenSnapz017.png roman, italic, and oblique (


Some fonts have wider and narrower versions of the letterforms. The terms for these versions vary by font maker, but will often be called things like condensed and expanded. These fonts adjust the horizontal width of the letters themselves.


Leading (pronounced like treading or fed-ing) is the spacing between lines of text. Back in the metal typesetting days they used strips of metal lead to separate lines, which is where the name comes from.

Kerning & Tracking

Track_Kern.png Kerning and Tracking ( Kerning and Tracking are adjustments to the spaces between letters of a proportional font. With tracking the extra space uniformly applied to all letters. With kerning the extra space allocated by letter pairs. This means that certain pairs of letters will have more or less space than other pairs, resulting in a more pleasing look. In some cases letters may vertically overlap to make them look better. Kerning values are very hard to generate algorithmically because it depends on the how the letter forms visually look to the human eye. For this reason well kerned fonts are created by hand by a font expert, and are therefore more expensive. The results can be well worth it, however, because the badly kerned fonts result in keming. Also available as a T-shirt. FirefoxScreenSnapz014.png Keming, from Ironic Sans.

Font Metrics

The actual letter forms have a specific vertical anatomy based on how we measure them. Together these measurements are the font's metrics. We use these measurements to decide how to put letters together to form words, lines, and paragraphs of text. FirefoxScreenSnapz018.png Font Metrics ( Of the various measurements in this diagram the most important is baseline. The human eye finds baseline aligned text very pleasing, and will notice the tiniest imperfections in this alignment. In GUI software it is important to align UI controls containing text (which is most of the standard controls) along the baseline of the text rather than the visual bounds of the actual control. For example, a button should be aligned with the text inside the button rather than the rectangular edges of the button itself. It may seem like a small detail but it makes a big difference. I once spent a year fixing bugs in the Windows Look and Feel for Swing, and the most visible bugs were vertical alignment issues. Yes, I spent a year of my life turning this: before.png into this after.png All in all, I still think it was a year well spent :)

Odds and Ends

  • Small capitals, aka: smallcaps, is simply smaller forms of the capital letters. Usually these smallcaps have the same height as the lowercase letters of the normal font. Smallcaps may be included in a font or generated algorithmically by shrinking the regular capital letters.
  • Dropcaps or Initials: special forms of the intial letter in a paragraph or chapter. They are often much larger than the regular text on the page and will 'drop down' into the lower lines.
  • Logical font: a font which doesn't actually exist, but will be replaced with a real font at runtime. For example, in webpage you can use the font 'sans-serif'. There is no real font named 'sans-serif', but the webbrowser will pick the user's preferred sans serif font and substitute it at runtime.

Categories of Fonts

In Roman languages (languages which use the 26 letters of the Roman alphabet plus various accent and punctuation marks) there are five major categories of fonts.


Serif letters drawn with features at the ends of their strokes. The serifs are the little feet we see in fonts like Times. These are some of the oldest type designs. The feet along the baseline help guide the eye from left to right, making them very 'readable' fonts. FirefoxScreenSnapz021.png Serif Font

Sans Serif

Sans Serif (french for "without serifs") are letters drawn with straighter lines and no feet. Their larger letterforms make them very legible, but can cause greater eye strain when used in long runs of text. Helvetica is considered the quintessential sans serif font. FirefoxScreenSnapz020.png Sans-serif Font


Script fonts imitate hand written letter forms. They are much harder to read than serif and sans serif fonts, and should never be used for body text.


Ornamental fonts are highly decorative and tend to work only at larger type sizes. They are often called 'display' fonts. They should never be used for body text (I'm looking at you, Comic Sans!). kruffy.png Type set in Baby Kruffy


Monospace fonts have letterforms that are exactly the same width, or are at least equally spaced. These come from the days of typewriters and old computers that could only move fixed distances. The are rarely used today except when the vertical alignment of columns matters. Examples include code editors and laying out tabulated data.

Text Placement

Most of our type terminology in software comes from the world of newspapers. In practice we have three major kinds of text when building webpages and software: body, header, and navigation.
  • Body: this is the bulk of your text organized into paragraphs. It is usually smaller than the other text and should use a simpler font that looks good at smaller sizes.
  • Header: this text in short runs (usually a single line or less) that must stand out. Headers usually appear at the top of a page or paragraph indicating that the reader should move their eyes here to begin reading something. Headers also look good with serif and sans serif fonts, but you have more freedom because the text is typically larger.
  • Navigation: this text is very short and is usually at the top or sides of the page or screen. It indicates the structure of the entire work, such as newspaper sections or different pages in a site. It should also indicate to the user how to navigate to that section. In a newspaper you would use page & section numbers. For software the text would be rendered as something clickable (a button, an underlined link, a hover effect etc.).

Quick Tips

Use the right font for the size

Not all fonts look good at all sizes. Some really shine at small sizes, others at large ones. Use the right font for your size. At smaller sizes you want fonts which are simpler and easier to read such as the basic serif and sans serif fonts. Try Arial, Helvetica, Times, Verdana, and Georgia. They are installed on virtually all computers and were designed to look good on screen at smaller sizes.

Use different font categories for different parts of text

Use a sans serif font for the header and a serif font for the body, or vice versa. It creates a contrast without banging you over the head with it.

Use truly crazy fonts only for top headers

Use the cool and crazy fonts only for the top most headers. In the example below I used a font meant to evoke mid-century Tiki-culture, with a funky light effect to suggest it's alcoholic origins. I only used this font in one place: the top most header of the page. Everything else is done with Helvetica; a standard sans-serif font. FirefoxScreenSnapz022.png Home page of Project MaiTai Use restraint. Pick one crazy font to use for your whole site or application and use it sparingly. If everything is different then nothing is. You can use a fancy font (somewhere between the plain boring fonts of body and crazy fonts of only top most headers) for headers within the page. And use one of the plain boring fonts for body text. Leave the crazy fonts just for the top most header.

Use color and style to create contrast

Use color changes or capitalization style instead of fonts to contrast between the headers, body, and navigation. For example, in recent versions of iTunes the headers in the sidebar are all capitalized and in a slightly lighter color with a hint of etching. iTunesScreenSnapz002.png iTunes 9

Bundle a font in your app

For the body text I still recommend sticking with one of the standards, but for your header font you can choose something a bit more distinctive. Here are some great places to get cheap or free fonts.

Avoid Cool Fonts

Don't use cool / cute / themed fonts unless the subject matter really warrants it. Your website on technology trends really shouldn't use a cutesy bubble font unless you are really targeting the tween market. FirefoxScreenSnapz015.png Sniglet

Just the beginning

Typography is an incredibly large topic. What I've covered here is just the beginning. In the future I'll cover text as part of the overall design and dive into the grid system. If you'd like to read more on typography, here are a few good resources: The 20 Do's and Don'ts of web typography.