Designers who are unfamiliar with certain characters or diacritics from another language sometimes make a wild guess about their correct shape. But if these glyphs are drawn in an incorrect or unconventional way, that will probably make the font useless for native users.
Typical errors include:
- Inverted question mark (¿) points into the wrong direction.
- Masculine ordinal indicator (º) looks like a zero instead of a superscript letter ‘o’. Wrong, because it needs to harmonize with ª (feminine ordinal indicator): it must have the same optical size and be placed on the same height.
- Double low-9 quotation mark („) is mistakenly drawn as single mark (‚).
- Diacritics like those in á ò ê ñ ü ž, etc. have inconsistent shapes and weights, or are different heights. Harmonize!
- Dotless i (ı) looks like a figure 1 (one) or a stick. No, instead it should look just like the letter ‘i’ without a dot.
- The Icelandic thorn (Þþ) and eth (Ðð) are malformed. Uppercase thorn (Þ) shouldn’t have a descender, nor should it be taller than other capitals. Its belly should (optically) be as large as in P. Lowercase thorn (þ) needs a full ascender and descender. Lowercase eth (ð) shouldn’t have a spur at the bottom right.
- Dot accent in ė ċ ġ ż etc. doesn’t harmonize with the i dot. Not good. Best practice is to make all dot accents the same as i dot, in terms of size, shape and position.
- Vertical caron in ď ľ ť creates a gap in words. It shouldn’t! It may look different from an apostrophe.
- There’s a German lowercase eszett (ß) in the ß slot of an all-caps or small-caps font. This is incorrect: the default capital eszett should look like a normally spaced double S (SS). You can include a real capital eszett (ẞ) by encoding it as U+1E9E.
- Sometimes the L-slash — Ł or ł — is created with a horizontal slash. The slash in the L-slash should always be angled.
- Diacritics Project – “All you need to design a font with correct accents"
- I Love Typography - On Diacritics
- Victor Gaultney: Problems of diacritic design for Latin script text faces (PDF)
- Context of Diacritics
- Diacritics Of World’s Languages
- Polish diacritics: how to?
- Before and After Diacritics (PDF)
- Thorn and eth: how to get them right
- Typography.Guru - How to draw a Capital Sharp S
- Typography.Guru - Capital Sharp S designs. The good, the bad and the ugly.
- Glyphs App - Adding Glyphs to your Font
- Glyphs App - German Capital Sharp S
- Glyphs App - Catalan Punt Volat
- Glyphs App - Accented Dutch ij
- Glyphs App - Turkish i
- Glyphs App - Polish Kreska
- Glyphs App - Romanian and Moldovan Comma Accent
- FontLab Studio 5 - Designing Accents and Diacritics (Video)
- Resources on designing diacritics - Alphabettes
- Greek typeface design – Texts to read, typefaces to study as examples, and links to resources for designers, compiled by Gerry Leonidas
- The relatively easy way to find out the quality of a Cyrillic typeface by Alexandra Korolkova
- Cyrillic Type Design: a Critical Context