Preparing figures and artwork for a document

Figure preparation turns an image, drawing or process into artwork that communicates clearly and remains readable in the finished document.

Purpose and form

Figures include photographs, shaded and line drawings, graphs and algorithms, and enhance most medical review articles, research reports and book chapters. ¹ A well-planned line illustration can explain a complex process without pages of prose, but a simple illustration may work better as text; a long process without decisions may be clearer as a numbered list. ²

Three forms serve different purposes:

• Flowcharts show workflow in complicated processes or procedures, replacing or accompanying process tables and making essential steps clear, especially where decisions are involved; arrange steps top to bottom, then left to right, joined by lines and arrows, with one concept per chart for long procedures and an overview chart to connect them.
• Diagrams help readers understand complicated equipment or procedures.
• Sample reports or forms show how to complete them; replace real names, addresses, identifying numbers and other actual data with fictitious information.

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A decision-tree algorithm can show conditional clinical reasoning, but decisions may depend on multiple variables that the diagram cannot fully accommodate. ⁴ Its connecting lines can also acquire errors during production, so an algorithm should be used when it is clearly the best way to present the decision tree. ⁴

One clear photograph may be enough: several images of the same physical finding may add nothing. ⁵ For example, a hypothetical report of three cases of sixth-nerve paralysis as the initial manifestation of a pituitary tumour would benefit from magnetic resonance images and perhaps a patient photograph, while three photographs showing the same ocular esotropia would be redundant. ⁵

Artwork terms

Line art uses black-and-white lines without shading, while halftone artwork includes photographs, drawings or paintings with fine shading. ^{6, 7, 8} A legend, also called a caption, gives a figure or table its title and may add explanatory information. ⁷ An overlay is a transparent sheet bearing graphic material to be superimposed on another page. ⁷

GIF compresses colour images, JPEG balances image compression and quality, and PDF stands for Portable Document Format, used by Adobe Acrobat. ^{9, 7} RGB represents colours through red, green and blue light. ⁷

Readability and image quality

Figures should be clear and large enough to read on screen and in print; publication proofs need checking for inappropriate resizing. ²

Technical preparation should follow these practices:

1. Make the figure understandable without reference to the text.
2. Identify each figure with an Arabic number and a corresponding text citation.
3. Create and submit the legend separately from the figure.
4. Describe digital modifications or enhancements of photographs.
5. Show photographic magnification with a scale bar within the figure.
6. Avoid faint lines in drawings.
7. Use consistent lettering throughout the figures.

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An explanation should stay close to its illustration except where manuscript legends are listed separately at the end of the text. ³ Published illustrations are often reused directly in lecturers' slides. ⁵

Photographic images need good resolution at creation; increasing a resolution setting later cannot recover missing detail. ⁸ X-rays may lack contrast, especially when enlarged. ⁸ When print uses grayscale but online publication uses colour, check that colour distinctions survive black-and-white reproduction; a black-and-white photocopy can help assess this. ⁸ Colour-art requirements and any publication charges should be checked with the journal. ⁸

Working with an illustrator

A line drawing can show anatomy more clearly than a photograph, and some drawings can be prepared by the writer or produced on a computer if their quality is comparable to other line art. ⁶ When working with a professional illustrator, direct contact helps establish how to collaborate, and a labelled rough draft can provide the starting point. ⁶ Anatomical accuracy should be checked before artwork is finished because later alterations are expensive; for example, a vein medial to an artery must be drawn in that position. ⁶

Learning graphic-design terminology helps writers and designers share an understanding of the artwork needed before production. ^{10, 11} A publisher may redraw illustrations or print the supplied artwork, so the submitted version may become the final image. ⁶

Combining captured images

In 2012, SnagIt for Mac and PC captured screenshots, images, webpages, videos and selected portions, opening and saving them automatically in an editor. ¹² It could cut and combine images, add call-outs and effects and save graphic formats, including assembling six graphs supplied by authors into one manuscript figure or creating tutorials. ¹² Video output was limited to AVI, and a home-and-work licence cost $39.95 after a 30-day trial. ¹²

Submission

The journal's instructions determine electronic submission and file organisation, and the graphics program used to create graphs, charts or diagrams should be identified. ¹³ Questions about adapting PowerPoint slides or using Illustrator or other software can be directed to the editorial office. ¹³