Paint advice?

Hi folks, I did some body and paint work in the '70s. We used a lot of acrylic enamels with catalyst. I remember using Ditzler PPG paint. Seemed adequate at the time. I'm also a model builder and just getting back into paint. I have a Sata MiniJet and plan to use single stage Limco Urethane on my current project. It will be at least two colors. Any advice on how to get a very smooth transition from one color to the next? I'll be painting a checker board pattern and would prefer very smooth edges. Thanks!

 

THAT IS YOUR INTRODUCTION?

 

https://www.jalopyjournal.com/forum/threads/the-h-a-m-b-rules-guidelines.44274

READ THIS

 

Urethane clear it after artwork ! Then wet sand and polish your dirt out