thisfits:

Mere hours after expounding at length on an “inviolable” key to wearing patterns—not wearing the same pattern at the same scale—Parisian Gentleman came across this stunning counterexample. The scale of the checks on the jacket and the shirt very nearly match, and yet the ensemble lacks the visual dissonance one would expect.

Lesson learned: study the “rules” of dressing well, but don’t be overly dogmatic about them, either.

That said, wearing two or more patterns of any scale is an advanced sartorial move. Proceed with caution.