26 Joe Carducci/Gretsch Guitars 9 months ago When checking the intonation at the 12th fret, GENTLY depress the strings. If you squeeze too hard with your finger pressure, it will pull the string sharp in pitch causing you to believe the intonation is off. When securing the bridge base, the factory uses a jig that places the bridge in the proper location. It's bullet proof! From there, fine tuning is achieved by the individual bridge saddles. 100% of the time when confronted with this issue with players, either on the phone or in-person, the outcome is as described above. Also know as the string vibration sustain decays after its been plucked, it will slowly drift sharp. Therefore, use the initial attack as your point of reference when checking intonation. Plus, always have a fresh set of strings on your guitar when checking the intonation. If you don't follow the above rules, you'll just be chasing your tail.