How to apply a panel line wash.. Here I’m using Deep Grey PLW from @ammomig After a gloss varnish to seal in decals and paintwork, you will be left with a smooth surface perfect for applying the wash. I usually start with applying it to the panel lines specifically to make sure they get filled properly and the colour is correct, once they’re all covered i move on to the rivets. I find if you follow the rivet lines instead of individually dotting the wash, you are left with essentially a shadow.