Originally Posted by Marcus26

Paper tuning is useful, but not in the way most people think.
Up-down tears indicate a high or low nocking point
A left-right tear indicates either poor centreshot. If moving the centreshot does not change the tear then it is likely hand torque. Get a good shooter to try also in this case.
It can show up other issues in teh cam areas as well, but this is rare.

It won't show arrow spine.