Non-resin??

[foto-phreak.livejournal.com]

I'm wondering what I could use as an alternative to resin but still get the hard gloss plus non-yellowing properties.

I want to do crafts with my niece and I really want to do bottlecap art... usually, I would think you would pour something like resin inside to cover the paper and any trinkets. But I want it to be something she could do on her own. I've seen that Crystal lacquer stuff and wondered if that'll work?? would that dry hard, look glossy, fill the cap and not turn yellow??

if not, is there anything else that might do this without her having to try to mix resin stuff and deal with the smell?