We recommend sealing the decals with Mod Podge and we have a Mod Podge application guide. While the decals stick well to the slick, non-porous band, they are susceptible to scratching of the ink, pushing on thin decal parts, and corners and points can catch on fabric enough to start pulling up the edges. With children beyond the baby stage, this can happen in a few days!
This is generally a much bigger issue with older children who are very active movers but with as easy as it is to put on and take off, we strongly recommend it for all bands. If you don't use it but needed too, the decals can be damaged before you realize it.
Mod Podge can help with large decals applied to curvature. The large decals can experience stress that is encouraging them to pop off.
Mod Podge can be hardly noticeable. Most of the helmets in our cranial band picture gallery have Mod Podge applied, and you can't see it in the pictures.
Mod Podge protects against scratching, and significantly helps reduce pulling on the thin decals and catching on fabric. The pictures below show the issues.
This image shows the classic case of a helmet being rubbed on fabric. The fabric catches on the corners of the letters, eventually lifting them up. But the rounded edges of the clouds don't catch (yet!) and are fine. Mod Podge can help this.
This image shows how points and thin sections fair when exposed to rubbing. The points break off, and the thin parts shift and break off. Rubbing is generally most significant on the back of the helmet because young children lay on their backs.
Mod Podge protects decals that don't have sharp points and aren't thin as well from abrasion wear. This images shows this little girl is active on her tummy as the name is worn, but the side decals are not.
We recommend five medium coats of Mod Podge, and periodic application (every other week or so on the back of active children's helmets).
We recommend you put two coats on per day, the first two before your child wears the band, and two more the next day, and the final coat the day after. This should fit the one hour per day your child is allowed to be bandless.
When applied to the proper thickness, Mod Podge removes easily. Work and edge of the Mod Podge until it can be lifted up, and then it will pull off in large sheets. The Mod Podge will remove without damaging the decals.