Actually, by the way, non flammable paint is allowed to pass through security, they do not ban all paint. Since you indicate you can check it I'm assuming it's non flammable, as you can only check non-flammable paint. So if it's non-flammable, this entire thread may be a waste

Because a half ounce is way below the 3.4 ounce restriction.

From the permitted and prohibited list

Non-flammable liquid, gel, or aerosol paint
Carry on - Yes - 3.4 ounces (100ml) or smaller container
Checked - Yes