Props How do I weather airbrushed on detail?

[TacoHombre]

I am currently repainting my nerf MA40 to the game colours, and I am wondering how I would weather things like the yellow stripe and decals.

I'm going to be airbrushing the details on with an acrylic model paint. I've done research into the topic and can't seem to find the right results (either it doesn't exist or I'm not using the right keywords)

Any help would be appreciated, thanks.

 

[PlanetAlexander]

I haven't done it myself yet, but I know of a couple of ways:
After sealing the paint, then masking the area for the stripe, the first method is to lay down some liquid latex, or something like toothpaste where you want the scratched off paint to be. Spray your airbrush paint and let it dry, then gently wipe away where the liquid masking is.

Second is to, again having varnished and masked before painting the stripe, lay down the airbrush paint, and once dry, take something like an old toothbrush and gently scrub the paint where you want the scratches to be.

 

[TurboCharizard]

I agree with PlanetAlexander's first suggestion of using a masking medium to have good control of the chipout and wear. The benefit to that approach is you can also follow it up with sandpaper and add even more weathering if you feel the need. Another similar approach that will get you a slightly different appearance is salt chipping.