If you use DuPont Croma Systems base coat clear coat you can activate the base colors with base maker, use what you need from each color then reseal the cans and they will be usable for many years to come. The clear coat is another story of course, mix only what you need, spray, and what is left is toast within hours after that. The great thing about the DuPont base coat is you can spray each color 30 minutes apart with an ambient temperature of 70 degrees or warmer and you can use the Dupont base maker activator in different temp ranges. The final really great thing about this system is that if you are spraying many different colors that take you days, weeks, or longer for that matter, no problem; the clear coat adheres to the base coat with no issues.

Bob