(mPDF >= 5.0)
In documents using core fonts only, only characters included in the win-1252 codepage are available in the Arial/Helvetica, Times or Courier fonts. If the document includes characters which are included in the other core Adobe fonts - Symbols, or Dingbats - these will be substituted. Because they are displayed using a different font they may appear ‘odd’.
In Unicode Truetype files, the limitation is whether the font file contains a “glyph” for each character in the document. Character substitution (i.e. substituting a different font solely to display that character) can be enabled by setting the configuration variable in config.php:
mPDF will try to find substitutions for any missing characters:
- if the character is in Unicode Plane 2 (SIP) i.e. Unicode value > U+20000:
- looks in the sip-ext font file (see Fonts in mPDF 5.x);
- looks in the font defined by `$this->backupSIPFont` in the config_fonts.php file
- looks to see if the character is available in the core fonts: Arial/Helvetica, Times, Courier, Symbols or ZapfDingbats
- looks in each of the the font(s) set by `$this->backupSubsFont` array in the config_fonts.php file
It is not recommended to enable this for regular use, as it will add to the processing time.