Every once in a while, we may send an update to the firmware that runs on Pencil. This is code that runs on Pencil that may enable new capabilities or improve performance. You should try to keep current with the latest updates. You can see a list of all firmware versions and instructions for checking your firmware version here.
Paper 4: While you can check your firmware version and battery status, it's not possible to update your firmware. This functionality will be returning to Paper in a future update. Tap on the Settings icon (sliders) top right, then "Stylus", "FiftyThree Pencil", and then pair your Pencil.
Paper 3: To upgrade your firmware, you will need to download the free Paper app, which you can find here or by searching the App Store for "Paper by FiftyThree." You will need Paper version 1.6.3 or newer. Open the Paper app and then tap your profile picture top-left, then "Settings", and "Pencil." Some supported third party apps will show you an "Upgrade Firmware" dialog and take you to this menu automatically.
Most updates will take less than 10 minutes. Very important! Make sure not to close the Paper app or turn your iPad or iPhone off while the update is happening. You should also keep your Pencil close to your iPad or iPhone.