I was watching Amazing Wedding Cakes and Christopher Garren's staff was spraying a luster on the cake. It wasn't an airbrush, like a spray bottle almost. Does anyone know what may be the trick here? Is it really a spray bottle with luster and alocohol? Or is it something more complex?

They do sell aerosol cans of luster. I've tried it it but didn't care for it. It's expensive and difficult to get an even coat on a large surface. I suppose with practice it may work well. But I didn't have the time or $$ to burn.

Or are you talking like Windex spritzer type spray? You could probably make your own with luster and vodka. Though I think the regular windex type bottles might give an uneven, spattery effect. Anything with a finer mist might clog. Worth testing though.

it was a small hairspray type of bottle that was clear on the bottom. it was hard to tell if it was aerosol or pump. my grandma told me once that you can buy air cans for airbrushing. I wonder if it was something like that.

I have a can of pearl spray but I don't like it, I feel it sprays much too heavily.

I really like the ready-made airbrush pearl, for use in an airbrush. Doesn't clog the nozzle like mixing luster dust can, and its a nice light coverage so you can choose how heavy you go on it.