Anyone here paint cars as a hobby?

Using the omni products and omni DP I have noticed more shrink back as apposed to the other PPG stuff. We can't afford to have stuff come back so we use the good ppg and glasurit stuff the first time.
What do you mean shrink back, I been using it for years and never had a issue with it, I use it for overalls and spot repair. Its a catalyst product, If its shrinking its either not cured before top coat or its not being mixed properly.