Often a certain amount of research is required to obtain an understanding of the anatomical environment and the medical procedure. Imagining interaction of forms plays a major part in the creation of a pencil sketch, which is the first stage to be reviewed by the client. After the illustrator goes over the pencil sketch with the author, changes can easily be made. The next step is the rendering of the final artwork. There are several techniques that may be employed, each of which draws on years of experience in illustrative technique.
Line drawings are the most economical to reproduce and are often preferred by publishers.
Like the traditional process followed by our ancestors, a pen with nib is dipped into black ink. Certain line drawings, however, can be produced on the computer. Subtle effects can be achieved on it with variation of grays and line weight. This is most suitable for diagrammatic illustrations such as drawings interspersed with arrows and type, diagrams clarifying ultrasounds or x-rays, or a series with minor variations of one main drawing. Most color illustrations, either simple or complex, are now done on the computer.