This post is a quick resource with condensed tips for isometric illustration. We begin by creating a custom isometric grid. Then, we use a formula for figuring out the dimensions for creating isometric artwork in the correct perspective.

Use the Line Segment Tool

The often-overlooked Line Segment Tool is my preferred tool for creating grids in Adobe Illustrator. Unlike paths created with the Pen Tool, line segments can be updated in the Transform Panel if you need to change the line length or angle later.

Here’s a tutorial by technical illustrator James Provost I recommend for creating isometric grids.

Summary of the tutorial steps:

Draw the first vertical line of your isometric grid with the Line Segment tool down the left edge of your artboard.
In Preferences > General, set Keyboard Increment to your desired line spacing. (I set my spacing to 28 px.)
Duplicate the line by holding Option/Alt as you press the right arrow key on your keyboard, and continue to cover the artboard with evenly spaced lines.
Group all of the vertical lines.
Select the group and double-click the Rotate tool. Enter 60º and choose Copy.
Use the shortcut Command/Ctrl+D, to duplicate step 5. You now have an isometric grid with 3 groups of lines.
If diagonal grid lines need lengthening, select a group of lines, ungroup, and change their length (all lines at once) in the Transform Panel. Then regroup the lines.

Do the Math

Grab your calculators! With a few simple measurements plugged into the formula below you can figure out the cube face measurement, and easily create 3D blocks using Illustrator’s 3D effects.

Go back to the original measurement you used to space out your isometric grid lines, mine is 28 px. We’ll call this number x. Here’s a formula to try out:

Divide x by .866

The resulting number is the height between grid intersections. (32.22 px is the height I get)

Multiply the height by 1.225 (3.22 x 1.225 = 39.6)

The resulting number is the cube face measurement, hang on to this number for the next step. (39.6 px is the cube face measurement for this example)

Use 3D Live Effects in Illustrator

Once you’ve created your grid, you can populate it with (almost) perfectly sized 3D cubes using live effects. I use these starter shapes for buildings and components, or as the framework for more complex art.

Take the cube face measurement from the formula above (mine is 39.6 px) and draw a perfect square that size.
Choose Effect > 3D Extrude & Bevel, then from the Position menu choose one of the Isometric settings.
Set the Extrude Depth to the same number (39.6 px) press ok.
Voila! Instant cube that fits on your new grid. Position it using Smart Guides to align the center of the cube to a grid intersection.
Play with the different Isometric position settings, changing the extrude depth. Isometric Top works for tall buildings. The beauty of this Live Effect is that you can scale the 3D shape, retaining the 3D Effect.

Expand Your Horizons

When you’ve finished editing the 3D shape, make a copy and expand it, Object > Expand Appearance. Then ungroup it to work with the resulting paths. Customize the shape with gradient fills, pattern fills and more.