Although there are several good italic instruction books currently available, there are many diverse opinions regarding the use of ligatures in italic writing.
From as far back as Arrighi, calligraphers have given instructions as to the rules of joining (ligatures) in Italic and the only consistent factor is their inconsistency!
The more you examine the subject, the more confusing it becomes. In writing Italic, some calligraphers are very sparing in their use of ligatures whilst others join up virtually everything. The books which give rules on the matter are not always the same rules! In a recent post, someone said that joins into the letter ‘a’ are never allowed and, indeed, I have seen that rule in print. And yet….look at the examples below! Even when ligatures are employed, the forms adopted can be quite different.
Hermann Zapf said -
“When writing quickly, connections between letters occur automatically. These can be different from one person to the next.”
Tom Gourdie said -
“Rules are given for ligaturing but should not be regarded as completely binding if handwriting is to be free and natural.”