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Scientific illustration often aims to depict an object not readily visible by eye or to help explain a concept or process. Before photography became widely available, hand-drawn illustration was the only way to record scientific and medical observations.

Today, medical illustration still plays an important role in communication – be that in teaching, education, research, patient care or public engagement.

Hand-drawn illustration

This kind of illustration, with a style unique to the artist, can reveal tiny structures such as the molecular composition of viruses and cells. To produce detailed paintings like this, extensive research of the scientific literature is first required to pull together information about where in the virus or cell major molecules are found, how big they are relative to each other and how they fit together. Colour is used to aid comprehension of a complex scene.

Illustrating Ebola | David S Goodsell. Filmed by Chadwick Trentham, edited by Gary Tobyn and produced by Chris Chapman. 

Digital illustration

Whereas traditional illustration uses media such as ink or paint, digital illustration utilises an electronic pen, tablet and software capable of replicating all the effects of traditional art media. The advantages of working in a digital format include the speed and ease of manipulating images, and the worldwide audience that the internet provides.

Digital illustration lends flexibility to the production of images: they can be created from scratch using computer software, or the technique can be combined with traditional media – for example, pen and ink drawings can be scanned and then digitally manipulated or coloured using computer software.

There are two types of digital image file: raster files and vector files. Raster images are made of hundreds of thousands of pixels organised into a grid, with each pixel holding colour information. An example of a raster image is a photograph. Vector files are based on mathematical commands and formulae, and are created using lines, curves and paths. Examples of vector graphics are logos and fonts.


Synthetic DNA channel transporting cargo across membranes.

Credit: Michael Northrop