Enhance your research with tips and tools from the experts on the PLOS Production Team. This post was written by Eric Cain and Mike Fisher and is part of our new Format for Success series where we’ll share advice for generating figures and graphics that make submitting a breeze. Stay tuned for more.
We know that preparing graphics files can be one of the most challenging parts of submitting your hard work to a publisher, when you would rather be observing in the field, experimenting in the lab, or conversing with the community. Like you, we want your research to shine and be noticed by your peers, adding to the scientific discourse and fostering collaboration in and across disciplines.
To help you create the best images possible and ensure a smooth article production experience, we’ve put together our top tips, distilled to a few major areas, for assessing your graphics files during submission:
- Consider raster images vs vector images – Raster images are made of pixels. A pixel is a single point or the smallest single element in a display device. Vector images are mathematical calculations from one point to another that form lines and shapes, which adjust to fit a monitor display and zoom.
Our journal article pages use raster graphics for in-article figure display, the lightbox figure viewer, and carousel thumbnails. Raster graphics are easier to create, store, and transfer across platforms, but limit resolution to 600 dpi. Alternatively, vector graphics are only available in the article PDF accessed online, but will result in a more detailed image at high zoom.
- Choose a resolution between 300 and 600 dpi – Effective resolutions below 300 dpi (dots/pixels per inch) often result in a blurry, jagged or pixelated image that is not optimal to publish, and resolutions above 600 dpi frequently must be resized or rescaled. We are required by the PLOS publishing platform, and community indexes like PubMed Central, to ensure content adheres to these resolutions.
- Combine multi-panel images – Often, it’s useful to exhibit a Part A, Part B, and Part C, all within one figure image. To create a multi-paneled figure from individual images, we suggest using a presentation program like PowerPoint, Word or GIMP to arrange your panels, create labels, and scale or size your figures. Multi-paneled figures need to fit into a single page or be broken apart into separate figures in order to publish clearly and accurately.
- Flatten image layers – Unflattened images can incorporate alpha channels, which include a transparent layer potentially containing “junk”, “artifacts”. Sometimes, an unflattened image can also render a figure into a complete black or white rectangle, obscuring all your content. We recommend that you flatten your graphics to combine all the layers into a single background layer, so we can ensure the quality of the output equals your intent.
- Compress file size with LZW compression – Data compression helps to reduce file size and also decreases time required to download and upload content. With compressed files, we can help you reduce the size of your article PDF, improving a researcher’s ability to access your work and send it to colleagues.
To help you assess your figure images, PLOS also offers authors a free, web-based imaging review tool, PACE, that evaluates figures against our platform requirements and fixes the most-common image issues, detailing any changes made, or informs the user what outstanding issues may exist. PACE compiles two, online review options in the form of typeset page mockups to give users an idea of how the uploaded image would appear in the final article. To use PACE, simply register with your email address: https://pacev2.apexcovantage.com.
Similar to undertaking a scientific protocol, PLOS’s production team follows specific rules to ensure that the accepted content is correctly transformed to XML and PDF in order to publish accurately in our journal sites and syndication targets. In short, graphic images must generally conform to the following:
- File format – TIFF or EPS
- Dimensions – Width: 789 – 2250 pixels (at 300 dpi). Height maximum: 2625 pixels (at 300 dpi).
- Resolution – 300 – 600 dpi
- File size – 10MB or under
- Figure files naming – Fig1.tif, Fig2.eps, and so on. Match file name to caption label and citation.
- Caption – Place within the manuscript as simple text, not within the figure file
We’ve posted additional graphics recommendations, as well as instructions for exporting graphics from specialized software, here: https://journals.staging.plos.org/plosone/s/figures.
We hope these suggestions make figure preparation even easier so you can spend more time advancing your field and we can publish your work faster than ever. We encourage you to email us at firstname.lastname@example.org with further questions.