Sail Number Bubbles

When rolling up my 2 month old sails, last night, I noticed that a couple of the numbers are starting to bubble up. They've probably only seen 6 hours of sail time in the past two months.

Is this normal? Is there anything I should do. I used a paint stick to smooth them back down. We'll see if it holds.

It happens fairly often. One thing that might help is to take an Exacto blade, or some other type of razor blade and make a very small cut in the center of the bubble, then carefully push the trapped air in the bubble from the perimeter inwards to the hole. As you do this the adhesive inside the bubble should stick. Try using a plastic credit card to smooth them out instead of a wood paint stick.