As upsetting as it might be that support for these older fonts is ending, it should come as no surprise. OpenType was not created to coexist with Type 1, but to replace it—and quite a while ago, at that. Support for Type 1 fonts has been ebbing away in OSes and applications for decades, and it’s somewhat surprising that Type 1 support still exists anywhere today. Adobe applications have been one of the format’s last refuges, and one reason Type 1 fonts have made it this far is because they were an essential and ubiquitous tool for so many designers and desktop publishers for so long.

Type 1 was practically the first desktop font format. Digital fonts existed before 1984, but they didn’t hit the mainstream until that year, when Adobe made its first and biggest contribution to desktop publishing: the PostScript page description language. Typography was a very important part of PostScript’s success, and Adobe created the Type 1 font format to allow PostScript users to employ different typefaces in their documents. (Adobe also created Type 3 fonts, but it was Type 1 that offered the best quality and performance in those early days.)

Adobe’s business exploded along with desktop publishing in the late 1980s, and soon there were thousands of Type 1 fonts in circulation, created by Adobe and other foundries. Eventually, Apple created the TrueType format as an alternative (and to escape Adobe’s licensing fees), but for many years, Type 1 fonts remained the gold standard of reliability for anyone with critical publishing workflows.

By the mid-’90s, software developers and users needed things Type 1 and TrueType didn’t have: Support for large character sets and the emerging Unicode character encoding standard (especially for complex languages like Japanese), cross-platform compatibility, and advanced layout features. For example, some early desktop typefaces were spread among multiple Type 1 fonts which held small caps, fractions, and other typographic niceties. They had to be stored in separate fonts because Type 1 was limited to 256 glyphs. OpenType was created to deliver much more typographic capability in a single, cross-platform file.

Ironically, even when a foundry attempted nothing more than to convert their Type 1 fonts to OpenType, minor differences were sometimes introduced not because functionality was lost, but because it was added. Combining a set of Type 1 fonts into a single OpenType font creates opportunities for new kerning between more letters, for example. Ligatures might appear automatically where they previously required manual intervention. Larger character sets might have more consistent spacing among accented glyphs. In other words, OpenType allows more typographic refinement by default, and introducing that into an older document might change it—for better or worse.

In theory, an OpenType font can be created from a Type 1 font by anyone with the right software, but there are many opportunities for such conversions to go wrong in minor or significant ways. (It might also violate your original software license agreement, so don’t attempt it unless you’ve checked that it’s allowed.) In the 2000s, most major foundries put a lot of effort into converting their font libraries and minimizing potential differences and incompatibilities, so it’s best to look for those “official replacements” first.

But even in the best cases, you’ll also want to watch for potential problems when you make the switch. An old document might have used a basic font along with expert fonts containing special characters like ligatures and swashes. References to those separate fonts in an old document might get lost in a switch to an OpenType version that combines them.

Spacing changes can be trickier. If the width of one or more glyphs has changed—even by a very small amount—it can cause a line break to change, which can have a ripple effect through an entire document or layout. Changes to kerning (custom spacing between two glyphs) can have the same effect. You’ll want to look very carefully for these changes, because they can be hard to spot—especially if text overflows in a frame and simply disappears.

Lastly, there might be design changes. Some glyphs might have been redrawn when the newer OpenType version was created. For example, some Adobe Originals designs were expanded to encompass more styles, like optical sizes (caption and display sizes), and in a few rare cases, certain glyphs were redesigned completely.

If you’ve ever opened a document with missing fonts, then you probably know what to expect when making replacements. You will be looking at a substitute, either deliberately chosen by you or automatically by your software. In the latter cases, those differences can be quite disruptive. When you substitute an old Type 1 font with the same typeface in OpenType format, presumably you have less risk of typographic chaos.

Keep in mind that older PDFs created with Type 1 fonts are safe—as long as their font data was embedded in the PDF when it was made. PDF readers, whether from Adobe or elsewhere, will continue to render these documents as they always have. Now is a great time to save PDF versions of important documents, before you upgrade to any new Adobe applications that no longer support Type 1 fonts.

OpenType emerged in the late 1990s as a solution to various problems with the prevailing font formats of the time—PostScript Type 1, and TrueType. One of OpenType’s primary functions was to serve as a container for either format’s outlines, which each use fundamentally different mathematics to describe them. While the idea was that the end user would simply see an “OpenType font” without regard to its underlying details, what emerged in reality was that an OpenType font file containing TrueType outlines came with a “.ttf” suffix, and an OpenType fonts with PostScript outlines came with a “.otf” suffix. That custom remains today—although, technically speaking, an OpenType font file with “.otf” is allowed to contain TrueType outlines as well.

OpenType font files are an evolution of the TrueType file format, so there is some sense to how “TrueType-flavored” OpenType fonts came to use a “.ttf” suffix, but it can also make it difficult to distinguish between TrueType and OpenType fonts.

Beyond its outlines, an OpenType font’s backbone is Unicode—an encoding standard that ensures that most letters, marks and symbols used around the world can be stored in a document with values that are consistent among all other fonts. While any OpenType font is applied to change how the text looks, the underlying information remains the same because of the text’s encoding, and OpenType’s reliance on Unicode makes it a better choice for typesetting that increasingly uses more languages and scripts.

Type Network’s library has many typefaces that began their life in the Type 1 format, and we can help you upgrade your old Type 1 fonts if we have a match. For the most part, if you can find the same typeface name with a search of Type Network’s library, you’ll be all set. If you can produce proof of any Type 1 font purchase (with a receipt or an invoice), we can also provide a substantially discounted (and, in some cases, free) upgrade. If you have a particularly critical case, get in touch with us and we can help you identify and prepare for any potential typesetting problems with an OpenType substitution, and find the most trouble-free solutions to help you through this transition.

It can be difficult when older software reaches its end of life. In the case of Type 1 fonts, preparations for this day began about 25 years ago, and most font users were gracefully, if not unwittingly, brought into the OpenType era long ago. If you find that you’re affected, the chances are there’s a convenient solution. Several members of the Type Network staff (myself included) have extensive experience migrating Type 1 fonts to OpenType. We and our foundry partners are here to help you through it.