As a Master Painter and Decorator you will have had considerable experience of painting and decorating. This is typically called "time served", meaning you've been painting and decorating for a significant number of years. You would continue to do all the tasks of a qualified painter and decorator, but might choose to specialise in particular techniques or types of project, depending on your background. You would become more closely involved in the ordering of materials for projects, which might involve visiting premises before the work is started. You would also be expected to assist in the preparation of quotations to secure additional work.