Current multimedia tools have fallen short of meeting the unique needs of a multimedia designer, presumably due to a misunderstanding of what those unique needs actually are. To better understand a designer's needs and practices, we interviewed (12) and surveyed (13) professional multimedia designers. From this study, we report on the process of multimedia design, design artifacts produced in that process, and tools used to produce those design artifacts. An important finding of our study is that a multimedia designer struggles to explore and communicate behavioral design ideas early in the design process. To address that need, we have developed an interactive multimedia storyboard tool called DEMAIS, which operationalizes a designer's ink strokes and textual annotations, producing a working example early in the design process. Using a working example, a designer can directly experience a behavioral design idea, facilitating the rapid exploration and effective communication of that behavioral idea.