While many of his paintings use a photographic reference as source material, he also works from direct observation, memory and imagination, sometimes employing all the techniques together. In non-adherence with his sources, Jacob edits and fills in detail, building relationships, emphasis, composition and color based on his own preferences and memory of his subject. Currently, Jacob is working on a book of transmutative geometric shapes, a project started as a challenge to find incarnations of non-repeating forms. Each page starts with a grid of simple arches or triangles, and each shape on the grid becomes more graphically complex as it is “read” left to right and top to bottom.