Depending on speed of reducer used - paint sets up from 1-4 hours hours after spraying. If you used a fast reducer - it usually sets up within an hour - a slow reducer - about 4 hours. When you buy your paint ask the guy about what reducer to use taking into account the room temperature and humidity you will be painting in. A faster set up is preferred because bugs seem to like the smell of the paint and love to land on it. I just painted a car on Saturday and a light weight bug with 1" wingspan got his legs caught in the wet paint and was doing the mambo. I left him there as it would do less damage than trying to remove him. I will buff out the little marks his legs left. Don't know how he got into the spray booth - it is well sealed - but he did. I usually leave the car untouched for 24 hours to make sure the paint is hard before touching it. Full cure takes place in about 7 days.