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How to draw in Illustrator: a step-by-step tutorial for researchers

Looking to elevate your figures and icons for science?

Animate your science magnifying glass and bacteria

If you’ve used the Icons tool in PowerPoint, you’re probably familiar with how flat they are. You want something with a bit more shine and sparkle… something… custom-made! How about making your very own science illustration?

Well, in fact you can create exactly that, in Adobe Illustrator.

Follow along with me to learn how to draw in Illustrator and create beautiful illustrations for science.

Learn to draw in Adobe Illustrator

Why choose Adobe Illustrator over Microsoft PowerPoint?

So, why Adobe Illustrator I hear you asking?

Adobe Illustrator is a much-loved program for graphic designers and illustrators all around the world. It is the industry standard software for vector illustration, and is our favourite vector software here at Animate Your Science, compared with other alternatives.

Illustrator logo and powerpoint logo

But I still hear you asking why YOU, a scientist, should use it? 👩‍🔬

Of course, we get it! You love good ol’ trusty PowerPoint. It is so familiar, so easy, so intuitive. It has gotten you this far after all. And we thank PowerPoint for its service.

Thank you for your service GIF

We are not saying you should abandon PowerPoint — it certainly has its place.

But why ride a unicycle to the shops, when you could ride a bicycle instead 🚴. In much the same way, we recommend Adobe Illustrator over Microsoft PowerPoint to create custom graphics and illustrations, because of the vast and user-friendly capabilities of the software, even for beginners.

Don’t get us wrong. Microsoft PowerPoint may still get you there in the end, but the journey may be a little slow and bumpy. 😂

Illustrator, on the other hand, is capable of taking you on a smooth and comfortable ride, taking your vector art to new heights. In fact, there is very little that Illustrator can’t do from creating crisp 2D graphics, through to complete 3D renderings.

Whilst Illustrator does have a steep learning curve, the tips and tools presented in this blog will help to guide you on this climb. Why not try out Illustrator today through a free trial? Check out the whole suite of Adobe programs here.

Follow our step-by-step tutorial below to create a beautiful but simple illustration of a bacterial cell. Whilst this tutorial is designed for Illustrator, feel free to follow along and test out your skills using any drawing software that you have access to.

Illustrator 101 for Scientists

Okie Dokie, let’s jump in and create a bacterial cell, for this tutorial we are going to create a schematic impression of the bacterium, Helicobacter pylori.

To start with, open up Adobe Illustrator and create a new workspace. Any size will do. Then you will want to open up the Painting Workspace 🎨 and Advanced Toolbar.

This will ensure that you see the same interface as me and can follow along easily. To do this go to the Window drop down menu, click Workspace and select Painting. Then within the same Window drop down, go to Toolbar and click Advanced. Any useful keyboard shortcuts will be indicated in brackets ( ). Command **⌘ (**Mac) will be synonymous with Control CTRL (Windows PC).

Adobe Illustrator workspace

Adobe illustrator toolbar

Now we are ready to go!

Helpful hint: Don’t forget to Save as you go! 😉 **

Draw an ellipse using the Ellipse Tool (L).

Adobe Illustrator Ellipse

Now add some additional anchor points ⚓️ to the bottom of the ellipse using the Add Anchor Point Tool (+).You can also access this by holding down the Pen tool, which will reveal a drop-down menu for the Add Anchor Point Tool. By default, the Toolbar only shows the Pen tool. Once selected, add two anchor points on the bottom part of the ellipse, about halfway in.

Anchor GIF

These anchor points allow us to modify the shape to be a little less perfect.

Adobe Illustrator Anchor points

Now it currently looks nothing like a bacterium, 😂 so let’s use these anchor points to manipulate the shape, and hopefully create something that at least resembles a bacterium. 🤞

Using the Direct Selection Tool (A) select the first anchor point, and you will see two handles extending from the central anchor point. You can move these handles up and down to manipulate the curvature of the path and can move the handles in and out to sharpen or flatten the curvature of the path. You can also physically move the anchor point, to change the overall shape of the object.

Animate your science Adobe Illustrator Anchor and Handle

In order to get the bacteria shape desired, move the existing central anchor point up. 👆

Adobe Illustrator anchor points

Next, select the anchor point we created on the left (🎶 to the left to the left 🎶). Then move the inner handle up towards the central anchor point.

beyonce GIF

You can also have a play with moving it in and out until you are happy. Then repeat this step, with the right anchor point we created.

Helpful hint: If you make a mistake and want to go back, you can still rely on trusty undo

(Command + Z / CTRL + Z).

Adobe Illustrator anchor points

Lastly, select the left-most anchor point and pull the handle straight up. This will flatten out the top. Again repeat this step on the other side, with the right-most anchor point to achieve the perfect bacteria shape.

Remember you must use the Direct Selection Tool (A) in order to move and manipulate

anchor points.

Adobe Illustrator anchor points

Once you are done fiddling with the anchor points and handles, and are happy with your shape we will move on to colouring the bacteria with your desired colour scheme. Simply click your shape with the Selection Tool (V), select the Fill (X) of the object, and assign a Swatch.

Adobe Illustrator colour fill stroke

For the stroke, also known as outline, we are going to create a custom brush to resemble the cilia on the outside of the bacterium.

This requires a few steps. First, draw a Line (\), then choose the Stroke (X) colour, by assigning a Swatch.

Helpful Hint: You can toggle between Fill and Stroke using the shortcut (X).

We also want to increase the weight of the stroke to around 3 pt

Adobe Illustrator line

Next, we want to make the line wavy. Now you could do this by adding anchor points and manipulating them as above to create a wave… OR you could use my cheat. 😉

To create a wave effect, 🌊 select the line with the Selection Tool (V), then click Effect in the top drop down menu, go to Distort and Transform, then select Zig Zag.

Adobe Illustrator

Within the Zig Zag effect box that opens up, reduce the Size to around 2 px, change the number of Ridges per Segment to 3 and select Smooth. Make sure that preview is selected so that you can view the look of your wavy line, and press OK.

Adobe Illustrator zig zag effect

Now that we have created a wavy line, let’s duplicate the line to create 3 more. I find the easiest way to do this is to Copy (Command + C / CTRL + C) and Paste (Command + V / CTRL + V).

But you can also duplicate by selecting the object of interest with the Selection Tool (V), and holding down Option/ALT whilst dragging the object.

Fantastic, now we have 4 lines, but we want each one to be slightly different. So let’s modify the Zig Zag effect for each. To do this, select the line with the Selection Tool (V), and click the Appearance Panel, and then Zig Zag, to open up the effect window.

Adobe Illustrator zig zag

Change the number of Ridges per Segment to 2, and do the same for the fourth line but change it to 4 Ridges per Segment.

Adobe Illustrator zig zag

By this point you should have 4 different wavy lines all spaced roughly evenly. If you need some help, you can use the Align functionality. Select all 4 lines with the Selection Tool (V), and click the Align Panel, and then click Vertical Align Top and Horizontal Distribute Space.

I personally like these lines to be slightly unevenly distributed, as I think they look more realistic. But you do you!

Adobe Illustrator align function

Alright, now we are ready to create our custom patterned brush. Select all 4 lines with the Selection Tool (V). Click the Brushes Panel on the side and click the New Brush button. Within the new brush window, choose Pattern Brush, and hit OK. This will create a stroke that repeats the selected objects as a pattern.

Adobe Illustrator new brush

Within the Pattern Brush Options window, select Auto-Between as the option for outer corner tile and the inner corner tile, and press OK.

Adobe Illustrator pattern brush

Wow, you have created a beautiful bacterial cell with cilia 👏 … But hold on, we are not done yet!

Adobe Illustrator tutorial

Next, duplicate the bacterial cell using whichever duplication method you prefer, and remove the Stroke colour on the second bacterial cell. Now carefully place this object over your bacterial cell, so that the cilia no longer protrudes inside the cell.

Adobe Illustrator tutorial

We are so close now, to finish off our bacteria we are going to add some flagella. Using the Pencil Tool (N), I’ve drawn 3 squiggly lines.

Adobe Illustrator pencil tool

Look at the beautiful bacteria that you have created.

Well done! 👍

schematic of bacteria

Dimension and Shading

Want to add some final finishing touches to your bacterium and really elevate your illustration. Try adding some dimension or shading.

To give the illusion of a more rounded bacterial cell body, try adding a gradient. A gradient is a fantastic way to give a 2D object a 3D appearance.

bacterial illustration

To apply a gradient, select the top cell body shape and click Gradient in the side panel and choose Radial Gradient.

By default, an applied gradient will have two colours, change the colour in the gradient bar to any colour you like. I like a darker blue for the outer edges to give that rounded “inflated” shape. To do this, drag and drop a colour from the Swatches panel on the gradient bar.

Change the Angle and Aspect Ratio to -7 and 40 respectively. Then offset the whole gradient, by clicking on the Gradient Tool (G) and physically moving the gradient to be off centre. You can also have a play at moving the Gradient Sliders to achieve the best gradient for your image.

And voilà a gradient. 🙌🏼

Adobe Illustrator gradient tutorial

Another option to create some dimension without changing the colour is to add a shadow or some shading.

Illustrator has lots of options when it comes to shadowing and shading. Drop Shadow is a great option for giving a consistent all round shadow.

bacteria created in Adobe Illustrator

In order to apply a Drop Shadow effect, select the top cell body shape and go to the Effect drop down menu at the top, then go to Stylize and click Drop Shadow. I like to play around with the settings here, to change the opacity, offset and blur of the shadow.

Adobe Illustrator drop shadow

Feel free to experiment with some different colours and effects to create a different look. Or perhaps try to add a background or a petri dish.

After all, practice makes perfect!

Now go ahead and include this illustration, or another one you create, in your scientific poster, presentation, graphical abstract or infographic, for that WOW factor.

Challenge yourself

How did you go? Did you love creating a custom scientific illustration? Are you excited to put some new skills to use? Want an extra challenge, why not create a model of a eukaryotic cell next, something like the image below? Or better yet, try and design an image for your lab or one relevant to your research.

We have only just covered some basic drawing functions of Illustrator, but if you enjoyed this tutorial and want to learn more, keep an eye out for our next blog or subscribe to our newsletter and never miss a thing. 🙂

Looking for something more complex?

Animate Your Science can design you a detailed, accurate and aesthetically-pleasing graphic for everyone to see. If you have an upcoming poster, publication, grant or presentation, contact us to discuss how we can help you visualise your research today!

Until next time!


Dr Khatora Opperman

Dr Juan Miguel Balbin

Dr Tullio Rossi

How to Design an Award-Winning Scientific Poster - Animate Your Science Online Course
Adobe Illustrator course: by scientists for scientists - Animate Your Science online course
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