A bit of a departure from all these pristine paint jobs, I was going for the Winter Soldier damaged look.
I built my shield from the flexible flyer sled and it was a bit of a rush job (and my first one) so I made a few rookie mistakes.
1. I used a gauge to make my perfect circles, but then tried to freehand the taping of the circles instead of cutting them with the same gauge.
2. Figured out my mistake on the blue, but then then it didn't match the imperfect red inner circle.
3. And finally, I didn't leave bare metal in the blue for the star adhesion. In hindsight I should have just taped off the star completely.
Since I was going for the damaged Winter Soldier look for my Bucky Barnes cosplay, I'm not losing sleep over these imperfections. Results are attached. I'll need to do another black acrylic wash coat after stripping some blue and adding the star.
I made those mistakes so now you won't (unless you want to). You're welcome.
One mistake I liked: I painted the shield before stripping the back. When I stripped the back the next day, the stripping gel seeped around to the edges of the front creating a cool paint damage look along the outer edge. Also, dropping the shield multiple times (let's pretend it was on purpose) only added to the damage effect.
Black Acryclic, then dipped the brush in water
Waited about 1 minute, then wiped it off with a towel.