Scientific illustration may seem daunting at first, however there are some great reasons to try your hand at it!

First, as you draw, you are forming new pathways and connections in the brain. Secondly, each time you draw a piece, you are making some in-depth observations about it and may learn something new about the natural world! For example, I just did a Pileated Woodpecker piece and learned more about the sexual dimorphism between male and female Pileated Woodpeckers. I originally thought that only males had red feathers, but now I know that both males and females do, however males just have more! As you draw, what will you observe?

scientific illustration sketch of cat skull

Step 1: Creating a Sketch

Before you even put your pencil to the paper, ask yourself some questions about your subject. Why might it look the way it does? What function does your subject have? How does it connect to the rest of its ecosystem? And, of course, does my subject look normal or abnormal?

For example, some of the questions that I had as I observed this cat skull were, 1) Can I identify which type of domestic cat it came from? There are many different sized domestic cats. 2) What does a typical cat skull look like when it’s intact? This one is missing some of the dentition. 3) Can I infer, or discover, how the head of the cat correlates to the skull? The eye orbital seems large in comparison to the size of a cat’s eye. How does the zygomatic arch sit inside the head?

Once you’ve asked those questions and spent some time observing your subject, then make a very quick sketch. This is a rough, and sloppy step, just to provide you with a basic outline.

scientific illustration outline of cat skull

Step 2: Refining the Lines & Details

Between every single step and throughout the process, you should be continuing to ask questions and make observations. How do the fissures in the skull connect each bone segment? What are distinguishing features and have I included them on my paper?

After the sketch comes the time to refine the lines. There is no need to erase or clean up lines as you create a sketch. Once you’re happy with the sketch, clean up the lines and add some extra details. Here, I detailed out the teeth, rather than making them simple triangles. I added the shape of the bone fissures, and made sure that the ratios were right. Looking at the subject from as many sides as possible can really help!

scientific illustration ink line and grey wash of cat skull

Step 3: Pigment Lines (optional)

Once you are happy with your lines, consider what needs a little more “oomf”, or contrast. Are there portions that are less visible than others? These may be areas that you want to go over with pigment liners. Tracing over your lines isn’t necessary, but can really help boost contrast.

Follow along as I add the pigment liner and discuss next steps.

Step 4: Grey Wash

Grey washes are simple, light areas of grey to denote where shadows are. The grey gives an added dimension to your piece, and even if you are going to add color overtop, they will darken the areas naturally.

simple scientific illustration of cat skull

Step 5: Adding color

Now go crazy with the coloring! Remember, one subject isn’t just one color. There are many colors, shadows, and highlights. Try to use at least 3 colors to represent mid-tones, darker shadows, and brighter highlights. Also keep in mind that there is no true black pigment. Dark blacks are actually browns or deep reds, so while you can definitely use black colors, the highlights may actually incorporate a different color entirely!

Don’t forget to utilize the color of your paper! With my cat skull, I knew that the color of the paper was a similar color to the skull itself, so I utilized the negative space for my highlights.

Learning More

Are you interested in learning more about scientific illustration? Go to my calendar of events, watch my YouTube tutorials, purchase illustration workshop in a box! There are so many ways to discover the natural world, make some in depth observations about the ecosystems we share with flora & fauna, as well as ways to express your creativity!

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