A problem with fonts

One of the biggest problems about using fonts in TEX is encodings, that is the order the characters come in the font. For example, the default encoding for Adobe's Times-Roman font is the `Adobe Standard encoding':

=0 =0 =0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

The default encoding for TEX, however, is the `TEX text encoding'. The Adobe Times-Roman font in the `TEX text encoding' is:1
=0 =0 =0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

=0 0 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 00 to 10pt by by 1 <16 0

There are many other competing encodings: `ISO Latin-1', `TEX extended text' (or `Cork'), `Macintosh', the list is seemingly endless.

In addition, different encodings contain different glyphs. The TEX text encoding is supposed to contain a dotless `j' character, and a slash for building `ł' and `Ł', but very few fonts contain these characters, and their places are taken by black squares above.

The problem of incompatible font encodings is addressed in TEX by virtual fonts.