First, charcoal is rubbed onto the back of the drawing or print out...
The linework is traced down and made permanent by painting with umber acrylic paint.
An underpainting of acrylic washes approximates the final intended colors and allows for a single-layer approach where accuracy, unification and opacity can be achieved immediately.
Painting is commenced with the background done first for cleanliness.
Painting is done piece by piece, attempting a final render quality at once, while oil paint is wet, blend-able and consistent colors are used.
After all parts are painted, a second layer is added over the dry paint, adding further refinements and details.