I have been painting the basecoat for a tank model with a brush using tamiya's olive drab but I keep getting these lines of lighter colored paint. At first I thought that I hadn't fully covered the side I was painting but after three coats they still appear with each coat just in different places. When I look in the jar of paint I see a more yellow color that is seperated from the green and even after I stir the paint it is still there. Does anyone have any idea why this is happening and how to prevent it.
Thanks

You nailed it. The paint is separating. If you have stirred it, for as long as you can stand, it may be a bad bottle or a very old one. You can try adding a tiny bit of IPA to it. If this doesn't help, buy a new bottle.

Put a couple of bbs or fishing sinkers in the bottle to help mix the paint more thoroughly when you shake it. That might help.

Alright, I will try adding a bit of IPA and if that doesn't work I guess I will have to buy a new bottle of paint. Thanks for your help.

Thanks, I'll try that.