depends on what kind of film you are using. 669 and id-uv can be stored and peeled a couple hours later. i use a bento box to keep them from drying out faster. you can peel them when you get back to the car or home. most can be peeled later with little effect. some, like 667, tend to dry out faster and are harder to peel. some films keep developing, like 689, so you want to peel them in a timely manner.