Bob Mollema's works draw inspiration from ancient nature religions, mythology, modern art, underground comics, and old packaging materials. The artist is particularly interested in polytheistic pre-Christian religions, seeing their stories as allegories and personifications of forces in nature and human emotions. Through his art, he aims to convey the harmonious relationship ancient cultures had with nature.
Mollema mainly works with crayon, pastels, pencil, or oil paint to rebel against uniformity, seeking purity and authenticity.