The following are provided as general guidelines for figures in manuscripts submitted to AHA/ASA journals. Authors are encouraged to review the individual journal Author Instructions when submitting a manuscript to a specific journal.
For initial review, it is preferred that each figure and its corresponding legend should be presented together on its own page within the manuscript PDF. Full resolution figure files are not required at initial submission; figures for review can be uploaded as a single PDF or part of a complete manuscript PDF. For additional information on preparing figures for revisions and/or accepted manuscripts, please see Figure Publication Guidelines.
Image Preparation Guidelines
- No data within an image may be enhanced, obscured, moved, removed, or introduced by digital manipulation. Images gathered at different times or from different locations should not be combined into a single image, unless it is stated that the resultant image is a product of time-averaged data or a time-lapse sequence. The groupings of images from different parts of the same gel, or from different gels, fields or exposures must be made explicit by the arrangement of the figure (eg, using dividing lines) and in the text of the figure legend.
- Blots and gels need to be presented with as much context as possible (ie, panels should not to be cut up into individual blots).
- The use of touch-up tools, such as cloning and healing tools in Photoshop, or any feature that deliberately obscures manipulations, is unacceptable.
- Linear adjustment of contrast, brightness or color must be applied equally to controls and all parts of an entire image. Contrast should not be adjusted so that data disappear. Excessive manipulations, such as processing to emphasize one region in the image at the expense of others (e.g. through the use of a biased choice of threshold settings), is unacceptable, as is emphasizing experimental data relative to the control. Nonlinear adjustments (e.g. changes to gamma settings) must be disclosed in the figure legend.
- Supply a scale bar with photomicrographs.
- Authors must be prepared to submit the original, unaltered files from which the submitted figures were derived, if requested by the editorial office.
- For some AHA journals, upon revision, authors of manuscripts that contain cropped gels/blots will be required to submit a separate PDF file that contains the entire unedited gel for all representative cropped gels in the manuscript. Authors should label each gel as “Full unedited gel for Figure _” and highlight which lanes of the unedited gel correspond to those shown in the cropped images within the manuscript. Authors are encouraged to submit this file at initial submission, but it is not required at that stage. If the manuscript is accepted, the PDF of the unedited gels will be included in the online supplemental materials. Please check individual journal Author Instructions for additional info.
Data Visualization Guidelines
Figures representing data need to be designed and presented in a way that allows readers to understand and critically interpret the data. In general, authors are expected to adhere to the following guidelines:
- Bar graphs should be avoided except when showing counts or proportions. Continuous data and small sample sizes should be represented with figures that show the full data distribution, such as dot or scatter plots.
- When possible, all data points should be made visible in figures. Consider using semi-transparency or show gradients in scatter plots and flow-cytometry figures and symmetric jittering in dot plots.
- Consider adding a flow chart or study design diagram when appropriate. Flow charts should provide information about the number of excluded observations and reasons for exclusion at each phase of the study.
- Ensure that figures use easily distinguishable colors/lines/symbols and are colorblind-safe. Free resources, such as Color Oracle, are available to test figure colors.
For additional guidelines, information, and resources, please see the following Primer article published in Circulation: Reveal, Don’t Conceal: Transforming Data Visualization to Improve Transparency
Figure Label & Panel Guidelines
- Figure parts should be clearly labeled. Letters and labels must be uniform in size and style within each figure and, when possible, between figures.
- Labels for panels should clearly marked by uppercase letters (A, B, C, etc) and located in the upper left corner of each panel.
- Font used within the figure should be between 8 and 10 points for legibility. Label units of measure consistently with the text and legend, following AMA Style for unit abbreviations.
- Limit white space between figure panels and within each panel.
- Authors are strongly encouraged to limit the number of panels per figure to 6.
- Avoid headings on the figure. Heading information should appear in the figure legend.
Figure Legend Guidelines
- Provide a short title (in the legend, not on the figure itself) and an explanation in brief but sufficient detail to make the figure intelligible without reference to the text (unless a similar explanation has been given in another figure).
- Symbols and abbreviations must be defined in the figure legend.
- All image acquisition tools and image processing software packages used should be listed. Deviations from the above Image Preparation Guidelines, including nonlinear adjustments, must be indicated in the figure legend along with a description of the processing software used.
- For representative panels, the exact number of samples (n) should be listed.
- Statistical tests used should be described in each figure legend.
- If the figure is reprinted/adapted from another source, please provide a permission letter and include the source in the legend. If no language is provided in the permission letter, use the following sample: Reprinted from Butler et al, with permissions from Smith Publishing. Copyright 2005, American Society of Medical Research.
Figure Publication Guidelines
- Figure/Image files should be uploaded in TIFF, EPS, or PDF format with figure legends extracted and included with the Manuscript text file.
- Figures should be supplied at the highest resolution possible: line art at 1200 dpi; everything else including CT scans, radiographs, other halftones, and color images must be at least 600dpi.
- When possible, line art should be in a vector-based format, eg, PDF or EPS.
- Color files should be submitted as RGB (red/green/blue; not CMYK). Figures that will appear in black and white should be submitted in black and white
- Graphics downloaded from the Web are not acceptable for print. Web graphics, usually in GIF or JPEG format, have a resolution of only 72 dpi, which does not meet the standard for publication.
- Multi-paneled figures must have all panels assembled into one piece and supplied as one file.