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.
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-right, then the gear icon, and “Pencil.” Some supported third party apps will show you an "Upgrade Firmware" dialog and take you to this menu automatically. The option to upgrade your Pencil firmware is in this menu and can be seen in the image below.
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.