: If the pen feels slippery with four fingers, a three-sided rubber sleeve (pencil grip) can help you find a consistent and comfortable resting spot for each finger.

While "finger3mp4" sounds like it could be a specific file name, it is more commonly used as a shorthand reference to the —a handwriting technique where you use four fingers to control the pen instead of the standard three. Understanding the Quadrupod Grip

: Many people write this way their entire lives without issue. Unless you experience cramping or significant fatigue, there is generally no medical or ergonomic reason to force a change to a three-finger grip. Tips for a Proper "Write-Up"