optical-size

Show optical size information for a font.

Quick Reference

fontisan optical-size <font> [options]

Options

Option	Description
--format FORMAT	Output format (text, yaml, json)

What is Optical Size?

Optical sizing is a typographic technique where glyphs are designed differently for different point sizes. Small sizes need more open shapes and spacing, while large sizes can have more detail and tighter spacing.

Variable fonts can use the opsz axis for continuous optical sizing, while static fonts may have separate fonts for different size ranges (Caption, Text, Display, etc.).

Output

Shows:

• Optical size axis (if variable)
• Size range recommendations
• Design size metadata
• Named instances for sizes

Examples

# Show optical size info
fontisan optical-size font.ttf

# JSON output
fontisan optical-size font.ttf --format json

Sample Output

Variable Font with opsiz Axis

Optical Size: VariableFont.ttf
===============================

Axis: opsz (Optical Size)
  Range: 8pt - 144pt
  Default: 12pt

Size Recommendations:
  Caption (6-8pt):    opsz: 8
  Small Text (9-11pt): opsz: 10
  Text (12-14pt):     opsz: 12
  Subhead (14-24pt):  opsz: 18
  Display (24-72pt):  opsz: 48
  Poster (72pt+):     opsz: 72

Static Font with Size Range

Optical Size: FontText-Regular.ttf
==================================

Design Size: 12pt (Text)
Size Range: 11-13pt
Style: Text

Recommended for body text usage.

Size Categories

Category	Point Range	Use Case
Caption	6-8	Footnotes, captions
Small Text	9-11	Legal text, fine print
Text	12-14	Body copy
Subhead	14-24	Subheadings
Title	24-36	Headings
Display	36-72	Large headlines
Poster	72+	Very large text

Related Commands

• variable — Full variable font info
• info — General font information