Clear Coating the Sails
The sails can be used as is, However we highly advise against it in order to protect them from dirt and possibly a little UV, we sprayed them with clear polyurethane. This particular paint is PPG DU-1000.
When doing the clear coat use a HVLP (High Volume Low Pressure) paint system.
Also, this paint is really toxic to breathe, so you're going to need a forced-air breather system. you can build one from scratch using a filter mask and a small forced-air furnace fan connected by lots of tubing, We recommend renting or buying a commercial system.