Non-"sticky"clear paints?

Maybe an automotive paint product?

@Judi is on the right track. Automotive clear coat is the top finish that’s applied over the color coats on cars, and you can buy it in auto parts stores. Dries very hard.

It will be very glossy, but you can dull it with steel wool when it hardens.

Gulf Coast Paint Mfg. Inc. STAR-BRITE 340. NON-STICK POLYURETHANE CLEAR GLAZE COAT

Mod Podge!

Rustoleum has a clear coat. Go back to the hardware store where you purchased your spray paint. They should carry it there.

@redfeather Mod Podge is great on a collage, not sure about that over rustoleum.
If we were in the indoor arts/crafts department I was going to recommend a clear extender for acrylic airbrush paints, pretty much like that. But this sounds like it needs a tough treatments as otherwise recommended.

I like @SpatzieLover idea of the rustoleum clear coat, as that’s pretty guaranteed to have compatible chemistry and not upset the fine camo layers below it.

well la dee da…

No offense intended, I take my collaging seriously too (sometimes). And Mod Podge is an archival quality treatment.

I was teasing, no offense taken. I’ve been in a Mod Podge kinda mood lately