At our school, Community Cooperative Nursery School, we want children to create and explore without the distraction of worrying about getting wet or dirty. The children come dressed for play, and always keep at least one change of clothes in their cubbies. No one is required to wear a smock to participate in messy activities.
For some children this is very freeing. But some children are hesitant to paint or touch anything gooey unless they can immediately wipe their hands. These same children are often the most reluctant to wear cumbersome vinyl or plastic smocks. I make a simple apron style smock from an adult T-shirt that is very popular with the children in my classroom. I have gotten requests to share the pattern, so I made a you tube video to demonstrate.