General Figure Guidelines:
You are responsible for obtaining permission to publish any figures or illustrations that are protected by copyright, including figures published elsewhere and pictures taken by professional photographers. We cannot publish images downloaded from the internet without appropriate permission.

You should state the source of any images used. If you or one of your co-authors has drawn the images, please mention this in your acknowledgements. For software, you should state the name, version number and URL.

Number any figures separately with Arabic numerals in the order they occur in the text of the article. Include error bars when appropriate. Include a description of the statistical treatment of error analysis in the figure legend.

Please do not use schemes. You should submit sequences of chemical reactions or experimental procedures as figures, with appropriate captions. You may include in the manuscript a limited number of uncaptioned graphics depicting chemical structures – each labelled with their name, by a defined abbreviation, or by the bold Arabic numeral.

Use a clear, Times New Roman typeface (for example, Helvetica) for figure lettering. Use the same typeface in the same font size for all figures in your article. For Greek letters, use a ‘symbols’ font. Put all display items on a white background, and avoid excessive boxing, unnecessary color, spurious decorative effects (such as three-dimensional ‘skyscraper’ histograms) and highly pixelated computer drawings. Never truncate the vertical axis of histograms to exaggerate small differences. Ensure any labelling is of sufficient size and contrast to be legible, even after appropriate reduction. The thinnest lines in the final figure should be no smaller than one point wide. You will be sent a proof that will include figures.

  • Figures divided into parts should be labelled with a lower-case, bold letter (a, b, c and so on) in the same type size as used elsewhere in the figure.
  • Lettering in figures should be in lower-case type, with only the first letter of each label capitalized.
  • Units should have a single space between the number and the unit, and follow SI nomenclature (for example, ms rather than msec) or the nomenclature common to a particular field.
  • Thousands should be separated by commas (1,000).
  • Unusual units or abbreviations should be spelled out in full or defined in the legend.
  • Scale bars should be used rather than magnification factors, with the length of the bar defined on the bar itself rather than in the legend.

In legends, please use visual cues rather than verbal explanations such as “open red triangles”. Avoid unnecessary figures: data presented in small tables or histograms, for instance, can generally be stated briefly in the text instead. Figures should not contain more than one panel unless the parts are logically connected; each panel of a multipart figure should be sized so that the whole figure can be reduced by the same amount and reproduced at the smallest size at which essential details are visible.