Not exactly a protective coating but this is a specially formulated, continuously repositionable adhesive print mounting spray that can also be used to create a cleaning sheet to clean your printer's feed/pick-up rollers.

Traditional print mount sprays are usually designed as permanent adhesive applications. Re-Tac is different as it acts as a re-positionable spray - once securely positioned, your printed image can be removed and re-positioned many times without damage whenever temporary adhesion is necessary. It is the ideal solution for mounting print work which is short term or needing to be replaced over and over. If you require permanent adhesion then you should use a traditional permanent mounting spray.

As a secondary use, Re-Tac lends itself well to create a printer cleaning sheet. Simply spray Re-Tac to the reverse side of a heavy weight (200gsm +) A4 paper and allow this to dry for 10 minutes MINIMUM.
Now feed this sheet ADHESIVE SIDE UP, using the paper feed button, through your printer and this will remove and pick up all the fibres from the main feed roller that can cause poor paper feed. You can reuse the same sheet and do this process as many times as you like.