Dave, what are you using for a top coat, are you using lacquer or are you using a varathane type finish? It's the finish coat that is causing the wrinkles, and it's an easy problem to solve. What's causing the problem, is the lacquer based finishes. You won't have wrinkle problems, if you use water based paints for the base coats. If you use oil based paints, you risk the chance of wrinkles every time. What's happening, is that the lacquer is raising the base paint. It's reacting to the hardeners and chemicals in the paint. The two different types of chemicals used to make paint and lacquer, react to each other. You can get the wrinkle effect, if the paint is fresh or if it's been on there for years. It's how lacquer works with base coats, it tries to attach itself to to finish in the base coat of paint, rather than just lay on the top of the lower coating. Which is what a varathane type of finish does, it just lays on top of the previous coatingTo avoid getting the wrinkle effect, switch to using a varathane type finish. The chemicals in it, don't react to the chemicals in paint. I'm sure you can get a better understanding, if you did a search on the subject. I've explained it as I understand it, I hope you understand my explanation.
Len