Illustrator Introduction


YouTube Videos:

Introduction - Drawing a reaction tube (15:42)

Part 2 - Drawing molecular graphics (19:32)


PRC_Reaction_tube.jgp - Template for drawing the tube


In this tutorial we will learn the basics of Illustrator to create scientific graphics. As an example we create a figure that shows all the components you need for an Polymerase Chain Reaction (PCR). This will allow us to learn about the different tools that are very useful for graphic creating = )


Table of Contents


1.) Create a new document
2.) Drawing stuff

3.) Keep things simple

4.) Resizing and export to InDesign



1.) Create a new document


Go on *file* -> *New...* -> New Document Profile *Print*. As Illustrator is a vector based program, we can change and scale our drawings later on and adapt them later on. With the print settings, you cant go wrong. If you pick another setting make sure "[ ] Align New Objects to Pixel Grid" is deactivated (blue circle), as this will snap your objects to a invisible Grid and therefore limit your flexibility severely (Fig. 1).


Illustrator - New DocumentFig. 1: Align New Objects to Pixel Grid is very annoying, as it does not allow you to align objects precisely.



2.) Drawing stuff


You can use the *Pen Tool (P)* to draw lines, or use premade structures like *Rectangle Tool* or *Ellipse Tool* (Fig. 2).


- Make use of the shift key to keep proportions of objects

- For scaling / rotating use the *Selection Tool (V)*

- To work on individual points use the *Direct selection Tool (A)*

- deactivate "Strokes & Effects" in the General Preferences

- keep your line width consistent (1pt is a good line width)

- clicking without dragging will give you additional options like amount of sides (Polygon Tool)


Penn ToolFig. 2: Use the Direct selection tool to adjust the lines! (Blue)


You can use the Clipping Mask feature to "cut out" an object and apply a background for example, or you can use a Fill, Gradient of Mesh colour (Fig. 3).


Fig. 3: Different way of colouring objects.


There are several ways to manage your objects. Make sure to familiarise you with the following ideas:


- Use the Group function (cmd + g) to make object handling easier

- Use *Smart Guides* (cmd + u) and Ruler lines to position objects easier

- Use the Align panels to distribute and align objects exactly to each other

- Work with different Layers (also use the look and toggle visibility functions in the Layer panel).

- Use the Path finder to merge several objects into one etc.

- Use the Reflect and Copy functions to duplicate objects.

- Use the Outline view (cmd + Y) to see if your lines are properly aligned to each other.


3.) Keep things simple


There are many ways of creating graphics in Illustrator. Which one you chouse depends on your style and what you actually want to draw.

However try to keep it as simple as possible. Try to reduce the detail of your objects to a minimum. This not only makes it easier to understand your figures, it also reduces the amount of time you need to draw it.


However, reducing detail can be difficult in some cases. Take a look at Fig. 4! Lets assume the phosphate tail is important to you (Yellow bubbles), and you cut on the other rest of the molecule. You need to thing about, how much detail you need and how much you want to keep, to still give a good idea of the molecule.

If you only show the 2nd molecule from the right, people might think you did not understand it very well, because a (at least to them) essential part is missing). In this case i probably would go for the middle one, as is has a good compromise of detail and the essential features I want to highlight.


detailFig. 4: Different illustrations of Deoxyadenosine triphosphate (left), with decreasing level of detail (Imagesource).



4.) Resizing and export to InDesign


If your drawing is finished, scale down your Artboard (Tools palet left side, or shift + o, Fig. 5). You can place Illustrator files directly into InDesign. I recommend that for print.

If you publish a PDF for the web, export your picture as a png. Some PDF viewers display your lines in different thickness depending on your zoom, what can lead to strange effects. Also a png helps to defend you picture against plagiarism, as you graphic has a low resolution and is less attractive for stealing than a vector based file.


scaleFig. 5: Scale down the size of your Artboard to match your drawing.



Finally show your picture some people with background in your field. They might be able to spot mistakes that you missed or things that are not clear or confusing.


UP - Vasco Elbrecht - (2011-2014)