The Clear Gloss for Inkjet is not a waterproof material. We do not offer additional top coatings but some customers have used Krylon's Preserve It! for added protection from moisture. However, I would recommend samples for testing this overcoat spray on the Clear Gloss for Inkjet. If you have access to a laser printer, our Clear Gloss and Clear Matte for Laser are waterproof and should not require additional coatings. You are welcome to request free samples of any of these materials by visiting the link below. https://www.onlinelabels.com/samples