Fonts 101: A Font Primer


Over the next few days, I will be covering everything from font management apps to how to deal with font problems. By the end of the week you’ll hopefully have a solid handle on how to manage and troubleshoot fonts on your Mac. We’ll begin this series by taking a look at the history of fonts and the various formats that fonts exist in.

It might sound crazy today, but fonts were one of the first things that really got me interested in computers. Computer typography was a constantly evolving industry in the ’80s and ’90s. A certain part of my personal interest developed because I went to high school with a kid whose dad turned out to be a rock star of computer typography. You see, his dad invented a method to describe a font using a mathematical “language” rather than just a set of dots. John Warnock, along with partner Chuck Geschke, left Xerox PARC to start Adobe Systems to commercialize this breakthrough in computer science. The key to Adobe’s (s adbe) Postscript technology was the ability to describe a font as an outline rather than a set of dots. The bezier curves that made up the outline could be scaled to any resolution and then filled with the dots on the printer so that all the edges looked smooth. Totally tubular!

Steve Jobs got wind of Postscript and went to Warnock and Geshke to convince them to adapt their technology to make a printer language that would work with Apple’s (s aapl) forthcoming LaserWriter. The Mac was revolutionary, in part, because you could see fonts displayed on the screen that looked like the fonts you could output on a printer. What You See Is What You Get (WYSIWYG) was a huge selling point for the Mac and the reason for its early dominance in desktop publishing and graphic design.

Fonts and the Mac

Because Apple was involved with fonts and typography from the very beginning, the Mac has support for a number of different font formats as they have evolved over the last 25 years. Here are the major formats that are found on the Mac that you can expect to see on your own machine.

Type 1 Fonts

If fonts were people, Postscript Type 1 Fonts would be the old men that sit around on the porch and gripe about how things used to be back in the day. The original outline fonts, Type 1 fonts are printer fonts (outlines) which must be kept together with their corresponding screen fonts (bitmaps) in order to render the text on screen. Even though they date back to the 80’s, Type 1 fonts have survived to this day and are still present in the font library of many designers.

Because of the problems caused by separate screen and printer font files, Adobe released Adobe Type Manager as a utility to render the outline fonts on screen. This was largely a response to TrueType and was successful in making all the designers who had invested lots of money in collections of Type 1 fonts very happy. If you have Postscript Type 1 fonts around today, you will want to make sure that you keep them with their bitmap fonts.

Type 1 Fonts have the file type LWFN. This type ID came from “LaserWriter font.”

Bitmap Fonts

Bitmap fonts are really out of use in the operating system, but remain as a legacy item. Bitmaps are basically fonts that are rendered at a specific size to be displayed on screen. They are not outline fonts, but rather a grouping of dots or pixels. You should only see these in conjunction with Postscript Type 1 fonts.

Part of the reason that Bitmap fonts stuck around is that font faces are typically adjusted by the font designer at small point sizes so that the proportions look correct. Bitmaps were carefully designed for each point size to look right at different sizes. Adobe came up with “hints” and in Postscript fonts to make these small adjustments on the fly and similar techniques have been employed in more modern font formats. Thus the need for hand-tweaked point sizes has diminished over the years and bitmaps aren’t really needed.


If Type 1 fonts are the old men on the porch, TrueType fonts are having a mid-life crisis as they realize that they never really reached their potential and are being pushed aside by the new kids coming up. Invented by Apple and brought to market in 1991 along with System 7 to try and break the stranglehold that Adobe had on the desktop publishing and laser printer markets, TrueType fonts integrate the concept of screen and printer fonts so you only have to manage one file, called a font suitcase, which contained both. The format became widely popular for cheap or free fonts but, despite the sophisticated kerning and ligature features of Quickdraw GX and Apple Advanced Typography, never really took off among designers who continued to prefer the typefaces available in Postscript format.

Apple licensed the TrueType technology to Microsoft (s msft), so TrueType fonts are supported in both the Mac and Windows operating systems. Unfortunately, the fonts are implemented differently on each platform, so you will see Mac and Windows versions of the same font family in the TrueType format. Today, new TrueType fonts would only be released in the Windows format since the Mac also supports that format.

Because TrueType was envisioned as an alternative to Postscript, a number of TrueType fonts were created in character-width compatible sets for popular Type 1 fonts like Helvetica, Times Roman, and Courier. The familiar TrueType fonts that correspond to the venerable Postscript fonts are Arial, Times New Roman and Courier New. One particularly frustrating aspect of font management is figuring out which fonts are simply replacements for the same typeface in a different format so that you can standardize your designers on the same font.

The Mac TrueType fonts have the type FFIL while Windows TrueType fonts appear as .ttf files. Leopard is moving towards the Windows format .ttf files as the standard (as is everyone else).

Dfont files are a special case of TrueType where the font data has been moved in the data fork to support some of OS X’s unix underpinnings. These are only used for system fonts and you should never need to mess around with them.


OpenType was announced in 1996, but became available around 2000-2001. This technology was jointly developed by Microsoft and Adobe to add additional capabilities to fonts and resolve the lingering conflicts of managing both screen and printer fonts. In particular, OpenType supports unicode character sets and non-Roman scripts like Arabic, though word processing or page layout software has to be written to expose those features to the user. At this time, Adobe’s entire library of fonts have been converted to OpenType and every other major font foundry releases their work in OpenType as well.

Although Tiger showed considerable support for OpenType fonts, Leopard goes much further and also includes support for Arabic script OpenType fonts.

OpenType fonts are .otf files in OS X.

Suitcase Files

In the old days of System 7, suitcase files held both screen and printer variants for TrueType fonts. The name still survives in OS X as a file type, but the implementation of font files in OS X has completely changed.

System Fonts

Mac OS X requires several fonts in order to display the menu bar and other UI elements. Because of this, OS X will often not boot at all if fonts are missing. Because fonts are loaded at a low-level in the operating system, problems with fonts can cause system crashes or performance problems. Leopard introduced the new concept of protected system fonts that will be replaced automatically if they are removed from the system font library to prevent such problems. If you remove some fonts and see them magically reappear, OS X may be helping you out by replacing the system fonts it needs.

Microsoft Word Fonts

Microsoft Office for Mac, partly because of Microsoft’s history of developing font technologies for Windows and partly to make Office documents more portable between Windows and Mac versions, includes a number of fonts in a standard install on the Mac. Some of these fonts are duplicates of fonts included with OS X and some are required by Office to render the toolbars and other interface elements of Office applications. These fonts were originally welcomed because they were better than the system fonts, but now the Leopard system fonts have surpassed the Microsoft fonts. Office 2004 and Office 2008 install fonts into different locations, so be aware of that as you try to clean up your fonts on your system.

Adobe Creative Suite Fonts

Adobe Creative Suite installs a large number of fonts in Mac OS X. CS3 and later put these fonts in the system library, but CS2 and the original CS placed them in an Adobe directory. If you are using Creative Suite, then you certainly want a large font collection, but you will end up with duplicates between Apple-provided system fonts and Adobe fonts. One of the most common font problems I see is a designer that has multiple versions of Helvetica installed that eventually conflict with each or simply cause confusion when choosing the right font for a project.

Get a Handle on Your Fonts

Tomorrow I will cover five software programs that help you manage your fonts: Font Book, FontExplorer X and FontExplorer Pro, FontAgent Pro, Suitcase Fusion X, and FontCase. In addition, if you really want an in-depth understanding of how fonts work in Leopard, I highly recommend that you check out two e-books from TidBITS Publishing: Take Control of Fonts in Leopard and Take Control of Font Problems in Leopard. Sharon Zardetto, who has been writing about the Mac for over 20 years, has created a really valuable resource for designers and support professionals alike. Tiger versions are also available if you are still supporting 10.4 in your shop. These books cover font technologies in far greater depth than I have here, and also explain how to fix a myriad of problems that may crop up.


Jonas Smithson

In Mac OSX Finder, in list view, how should I distinguish between TrueType files and the bitmap (screen) files associated with PS Type 1 fonts? They both appear with an icon that says “FFIL” and are both identified in the Kind column as “Font suitcase”. Currently I guess which are the PostScript screen fonts because I see similarly named PS outline files adjacent to them in the list, but is there a more precise way to tell the two kinds of files apart?

Weldon Dodd

Hard to know exactly what the printer is asking for, but is the writing in your PDF file an image or is it selectable text? If it’s an image, then they want you to redo the layout with actual text so they can get a better print on the canvas totebags. If the writing is already text, then they want you to change the font used to something that they can work with.


I stumbled on this posting researching how to fulfill a request by a printer to resend a graphic with the text in “outline font.” As a novice, I’m a bit confused as to my options since I thought a PDF would serve the purpose for this job. Can someone tell me what they mean by outline font for printing a job (graphic and text onto canvas totebags) and my font options for reformatting the text on a MAC. Thanks for the font lesson!

Weldon Dodd

@harold – thanks for chiming in! I had a really hard time keeping the word count reasonable on this one, as you noticed. Thanks for adding to the discussion with the details on OpenType flavors. I didn’t know that about how some Windows programs only support the TrueType flavor of OpenType. I hope you will come back and comment on the rest of the series.

@jbelkin – Absolutely. That sentence about organizing Office fonts should not be read as an open license to just jump in and start moving fonts around. Anyone who wants to do so should really pick up Sharon Zardetto’s e-book. It provides step-by-step instructions for Microsoft Word fonts.

@sandbaggerone – Thanks! I hope you’ll come back.


You should point out to people that as much as you would like to clean up MS typefaces/fonts from MS Office – DO NOT move them. Ms apps will stupidly break even if you do NOT use the font – it needs it for some stupid reason that is MS.


You may have (intentionally) overlooked the fact that the opentype specification allows for opentype to be based on either postscript outlines or truetype outlines (referred to as “flavors”). Postscript-flavored opentype fonts have an otf extension. Truetype-flavored opentype fonts have a ttf extension which makes them extremely difficult to distinguish from a plain old truetype font. The Mac OS provides no visual or written distinction between the old ttf fonts and new truetype-flavored opentype fonts. It reads them both as “Win Truetype” fonts. This causes many Mac graphics people to freak.

There are subtle pros and cons to each “flavor” of opentype (otf and ttf) however they both work equally well for Mac OS X users. Truetype-flavored opentype offers compatibility with some Win programs that do not support postscript or postscript-flavored opentype.

This might seem too esoteric for general publication but as tech support employee for a major font distributor, I can assure you that much confusion surrounds this particular issue. Other than this oversight, you’ve done a good job (so far :)

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