Proofing and debugging OpenType fonts

Session 5

Saturday, 2 October 2021

8:00 AM CST – 9:00 AM CST




Fonts for South Asian and South East Asian scripts include shaping features that help correctly render text in the target language. To ensure that the features are correctly set in the font, it is important to test the font with all the possible combinations of letters, ligatures and marks. While there are font tools that show all the combinations that are handled in the font, there aren't many that can point out the ones that are not handled but required by the script. A new tool, called Hibizcus, does that by providing plenty of script and language data that help developers test the fonts for all the required combinations. Hibizcus also helps identify shaping errors by diving deeper into text strings that exhibit problems. This workshop will start with a brief introduction to OpenType shaping, and some of the features that are used to shape text in South Asian and South East Asian languages. It will then introduce the Hibizcus tool and guide the participants through the process of proofing their fonts with built-in data. It will finally walk them through the debugging process by taking a word or text string that is not shaped correctly. It will show participants how to dig deeper to precisely identify the problem areas. Participants will need an Apple Mac machine running macOS Big Sur (11.0) or later with Hibizcus installed. Hibizcus can be downloaded for free from the Mac App Store.
  • Muthu Nedumaran


    Muthu Nedumaran has over 3 decades of experience in designing typefaces for Indian and Indo-Chinese scripts. In the 80s, he developed bitmapped fonts for dot-matrix and laser printers. This changed the landscape of Tamil printing in Malaysia and Singapore at that time. Today, Muthu's typefaces are bundled into iOS, macOS and Android in some devices. Some these fonts serve as the default UI font. Muthu has also innovated and built fast and efficient input methods for all the languages he works on. The Ministries of Education in Malaysia and Singapore have been using his Tamil fonts and keyboards as the official standard for all their Tamil content since 2002 and 2010 respectively. Muthu is currently integrating all the font tools he has developed over the years into a unified app to help font developers easily proof and test their fonts across their target languages.

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