# `opbd`: Optical Bounds Table

The `opbd` table is an Apple Advanced Typography (AAT) table.

class fontTools.ttLib.tables._o_p_b_d.table__o_p_b_d(tag=None)

  Bases: `BaseTTXConverter`

  Optical Bounds table

  The AAT `opbd` table contains optical boundary points for glyphs, which applications can use for the visual alignment of lines of text.

  See also https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6opbd.html

  subset_glyphs(s)