Do’s & Don’ts: 6 Fonts That Break Arabic and Thai Layouts
Why Arabic and Thai Are High-Risk Scripts
Top Font-Based Failures That Break UX
Fonts Commonly Responsible for Failures
Real Case Study: Thai Public Sector Accessibility Failure
Where MoniSa Stands: QA Beyond the Font Dropdown
Typography QA Checklist for Global Teams
Final Word: Don’t Let Fonts Be Your Weakest Link
Why MoniSa?
Ready to Audit Your Fonts?
Typography Is Not Universal. It’s Script-Specific.
Fonts can make or break the global user experience. What looks clean and professional in English might render disastrously in Arabic or Thai. From broken ligatures and illegible diacritics to spacing failures and regulatory non-compliance, typography is not just a design layer. It is a functional cornerstone of multilingual content integrity.
As the world grows more multilingual, digital products must meet not only translation accuracy but also script fidelity. Arabic and Thai, in particular, pose intricate rendering challenges that require typographic and linguistic expertise working hand in hand.
At MoniSa Enterprise, we go beyond basic font checks. We integrate ISO-certified font QA into every step of your multimedia and localization pipeline, ensuring every script reads as beautifully as it looks.
Why Arabic and Thai Are High-Risk Scripts
Both Arabic and Thai pose unique challenges because they do not follow Latin-script logic.
Arabic Typography: Complex, Cursive, Contextual
Right-to-left directionality
Cursive flow with contextual joining of characters
Ligature dependence for visual and grammatical clarity
Diacritic use for pronunciation and disambiguation
Arabic script is not just a set of characters, but a fluid writing system. Each character has multiple forms depending on its position in a word. The connection between characters is essential to meaning and readability. Fonts that do not account for contextual shaping logic often display broken joins or substitute letters with their isolated forms, disrupting readability entirely.
Common Failures in Arabic:
Characters rendered as disjointed shapes instead of connected script
Diacritics placed randomly above or below the baseline
Lack of ligature substitution creates a staccato reading rhythm
Inadequate RTL support breaks line layout and justification
Thai Typography: Vertical Logic Meets Minimal Spacing
No spacing between words
Tone marks and vowel signs placed above, below, and around base consonants
Tight vertical grid with strict alignment rules
Line height must be exact to prevent overlap or truncation
Thai typography is governed by complex placement rules, where a single consonant may carry up to three diacritics in various directions. Without precise stacking logic and correct vertical metrics, tone marks can merge, float, or even fall outside text containers, making reading difficult or impossible.
Common Failures in Thai:
Vowel marks split across line breaks
Tone marks placed too high or too low, clashing with surrounding glyphs
Vertical overlap of stacked diacritics
Text cut off in mobile or compressed environments
Top Font-Based Failures That Break UX
Broken Character Joins (Arabic) Outdated or rigid fonts fail to execute contextual shaping logic, displaying isolated glyphs where connections should exist.
Overlapping Diacritics (Arabic and Thai) Incorrect stacking order or insufficient glyph space causes tone marks and vowels to collide with adjacent characters.
Misaligned Tone Marks (Thai) Tone marks appear too far from their intended consonant, especially in bold or italic font weights.
Excessive or Inconsistent Line Heights Improper font metrics either compress glyphs vertically, leading to collisions, or introduce large gaps that disrupt content flow.
Justification Glitches (Arabic) Justified paragraphs can stretch Arabic characters unnaturally, altering meaning or creating a broken visual rhythm.
Platform-Based Rendering Variability Fonts that look acceptable in Word or Figma may break on Android or iOS. Inconsistency across platforms introduces untestable risk.
Source : Do’s & Don’ts: 6 Fonts That Break Arabic and Thai Layouts
