In 1983 he entered the highly competitive market of freelance illustration, and by the end of that decade had established himself by working for clients such as the National Wildlife Federation, NASA, Focus on the Family, Christianity Today as well as other large corporations, agencies and private collections. His ability to convey intangible aspects of drama and spirituality in his subjects attracted clients who commissioned works for inspirational book covers, magazines, and television shows. A series of paintings he completed for NASA, depicting various scenes of the space program, is a remarkable example of his ability to express the emotional elements of a moment. The paintings not only describe the scenes in all their detail, but also communicate the scale, intensity and wonder of man's heroic attempts to probe the heavens.

Nathan is very much a contemporary painter with a strong foundation in classical art. His paintings include oil on canvas and also a multimedia approach, incorporating other drawing and painting methods and materials in the same piece. The figures are painted using live models, carefully chosen, then photographed under Nathan's direction. He starts each project by producing a detailed pencil drawing, the result of any number of exploratory sketches to determine composition and light and dark values. The drawing is then transferred to the painting surface, and he begins with an underpainting. Working on the floor, he covers the canvas with a thin oil wash of colors designed to set up a warm and cool interplay which subtly shines through the layers of paint to produce a glowing depth and richness. Next, moving to the easel, he begins painting the actual image, first pulling out the light areas, thenapplying the paint to describe form, color and detail.