1. Open your 3D processed spectrum. 2. Click on "show F2-F3 plane" (button "23" in TopSpin 3.2) xfb 3. Select plane orientation: "23" 4. Select plane number: "1" 5. Enter new PROCNO: can be "231" 6. Interactive phase correction 7. Add 3 points, then "R" - start the phase correction on rows 8. Phase and save. 7. Save for 3D spectrum (second button after "R") 8. Return to 3D spectrum. 9. process: tf3 and tf2 check you F2-F3 plane and enjoy! ;-)