Which preposition to use with unreadable

in Occurrences 2%

There is something genuine, honest, gentlemanly, and unreadable in him.

as Occurrences 1%

In the glow of the hanging lamp, Starr's lined, grizzled features were as unreadable as carved bronze.

of Occurrences 1%

No other excuse at least can be given for the composition of one of the heaviest and most unreadable of dramatic performances, interesting now, if interesting at all, solely as a curious example of the result of bestowing great powers upon a totally uncongenial task.

on Occurrences 1%

[Footnote 1: "(unreadable on original page) in Dryden's 'Conquest of Granada.'

Which preposition to use with  unreadable