For better or worse, virtually no font foundry currently offers “free or paid upgrade options” for Type 1 fonts that they licensed in the somewhat distant past. (Remember that OpenType CFF and OpenType TTF fonts were introduced at the start of the current century, over 20 years ago! It has been quite a few years since any major font foundry has offered fonts in Type 1 format!)
The good news is that at least in terms of what one may call “classic” Linotype Type 1 fonts, there are newer versions of such fonts that can be licensed through various Monotype-controlled vendors either in OpenType CFF or OpenType TTF format (OpenType CFF is effectively a Type 1 font, Bezier outlines, in an OpenType wrapper. OpenType TTF is effectively a TrueType font, quadratic outlines, in an OpenType wrapper). The good news is that such newer versions typically have major improvements such as Unicode encoding, improved metrics, built-in ligature and alternate character support (small caps, multiple figure types, etc.) that can be automatically used by modern layout programs and word processors, as well as often dramatically extended character sets supporting multilingual documents. In some cases, the actual design of some glyphs within a font have been updated or “improved.”
On the other hand, with such changes, depending upon the existing content you have, you may find either minor or major layout changes and possible character encoding issues when migrating from an a Type 1 to an OpenType version of what purports to be the same font. (This is the primary reason that most font foundries gave an updated name to the OpenType version of the same design!) In general, at least in terms of font metrics compatibility, if you migrate from a Type 1 font, you should license an equivalent font in OpenType CFF format.
In terms of “simply converting” you should be aware that many if not most font EULAs (End User License Agreements), especially for fonts from Linotype or any of the foundries owned by Monotype, specifically prohibit such conversions by licensees, (Note that I am not a lawyer!) In terms of such conversions, you can expect some possible text relayout due to differences in interpretation of metrics. You certainly won't have access to OpenType features that weren't available in the original Type 1 font format.
For better or worse, I would personally advise that you bite the bullet and license current equivalent versions of your old Type 1 fonts, understanding that you will need to carefully review any text formatted with the new fonts.
- Dov Isaacs