Each figure must be numbered, and each should be called out in the text in consecutive numerical order. Importantly, a figure should be no larger than approximately 11.5 cm (4.5 in.) × 16.5 cm (6.5 in.), which is the size of the print area on a single journal page. A figure should have a caption that is brief and self-explanatory, and that defines all nonstandard abbreviations used in the figure. Captions must be listed separately, on a page by themselves; however, each figure must be clearly identified (numbered), preferably as part of its filename. The artwork should be professional in appearance and have clean, crisp lines. Hand drawing and hand lettering are not acceptable. Figures should not use color in any way. Shades of gray do not reproduce well and should not be used in charts and figures. Instead, stripe patterns, stippling, or solids (black or white) are good choices for shading. Photographic images can be submitted if they are saved in JPEG or TIFF format at a resolution of 300 dots per inch (dpi) and sized to fit within the single-page dimensions, 11.5 cm (4.5 in.) × 16.5 cm (6.5 in.).