Image sources and their licences
Reusable scientific images come from public image databases and from icon and illustration libraries, and each image's licence sets whether and on what terms it may be reused.
Image databases
The Images database (www.ncbi.nlm.nih.gov/images), new in 2011 and linked to PubMed Central, let a user search for figures and illustrations, some of which may be freely reproduced. A search by keywords such as topic or author returned a list of citations to medical and life science journal articles, along with thumbnails of the relevant figures they contain. Simple topical searches could return thousands of hits, so a user might need to be quite specific or to use the Advanced Search feature. Images and data could be saved to a personal collection and shared with others through My NCBI. A figure found there could be reproduced without charge as long as its article was labelled as distributed under the terms of the Creative Commons Attribution License or a similar licence and the original author and source were credited.
In 2011 the Cell image library (www.cellimagelibrary.org) was a public repository of images, videos and animations of cells, capturing a wide diversity of organisms, cell types and cellular processes. It was hosted by the American Society for Cell Biology and supported by the National Institute of General Medical Sciences and the National Institutes of Health. Its purpose was to advance research on cellular activity, with the ultimate goal of improving human health, and it was designed as a public resource primarily for research and secondarily as a tool for education. Its images came from historical and modern collections, from publications and by recruitment. Through high resolution, videos and animations, it enabled viewers to observe cellular architecture and functions. It could be browsed by cell process, cell component, cell type and organism, or by its most recent images, and clicking an image brought up an enlarged version with a detailed description. Close to 2,600 of its images were in the public domain, while the others were copyright protected or licensed under a Creative Commons Attribution License.
Icon and illustration libraries
In 2025 these icon libraries were among the tools and resources for prototyping visual aids:
| Name | What it is used for | Website |
|---|---|---|
| General icons | ||
| SVGrepo | Large scalable vector graphic icon library, with a search function for icon style and appearance (colour, line style). | https://www.svgrepo.com |
| Font Awesome | Unicode-based icon library with many free icons, downloadable individually or in batches as scalable vector graphics (SVG). | https://fontawesome.com |
| PowerPoint | Built-in image and icon libraries and many pre-drawn shapes that are free to use. | |
| Biology icons | ||
| Bioicons | Expanding repository of biology and laboratory icons, from petri dishes to model organisms, available under free licences (CC0). | https://bioicons.com |
| NIH BioArt | Free, high-quality vectors and icons created by professional illustrators. | https://bioart.niaid.nih.gov |
| Phylopic | Shapes of numerous animals, plants and further model organisms, for example for phylogenetic trees. | https://www.phylopic.org |
| Reactome | Scientific pictograms and chemical drawings for free reuse, with users encouraged to upload their own pictograms to share with the scientific community. | https://reactome.org/icon-lib |
| SciDraw | Free repository of high-quality icons. | https://scidraw.io |
| Medical icons | ||
| HealthIcons | A global volunteer effort to create common icons for many specialised medical scenarios, available under a Creative Commons licence (CC0). | https://healthicons.org |
| SmartServier | A free collection of medical drawings from Servier Medical Art that can be downloaded as a full slide deck and used with attribution. | https://smart.servier.com |