Rainbow Strokes for Illustrator Folks

3 min readNov 10, 2021

TLDR you can create those 70’s style noodly illustrations with this. Fun, easy, and way easier than trying to strong-arm your strokes in the Appearance window.

Note: In place of CTRL please use the ⌘ key on Mac.

Make rectangles with the colors you’d like in your stroke. Ideally, all of those rectangles are the same width across, it’ll look cleaner that way.

Step One

Make a series of rectangles as pictured.

I suggest making one, hit CTRL+C then CTRL+F, hold SHIFT, move it down a bit, then selecting that second one, CTRL+C, CTRL+F, then CTRL+D. You can do this ad-nauseum but I suggest between 3–5 for the 70s vibe.

Color them, then select them all, hit CTRL+G to group ’em. Moving forward I will be calling this group “rectangle group.”

Once you’re happy with it, you’re ready to pop it into your Brushes. Be sure to open that by going to Window>Brushes.

Drop your rectangle group into Brushes Window, select ART BRUSH.

Step Two

Select your rectangle group, drag and drop it over to your Brushes Window.

It’s gonna ask what kinda brush this is. Select ART BRUSH.

💀 Failing to select the correct type of brush will result in a brush type you aren’t seeking to create. You’ve been warned. 💀

BE SURE to select the left-and-right orientation. This is crucial.

Step Three

You want to be sure Stretch to Fit Stroke Length is on and the Direction is Right-to-Left or Left-to-Right.

Name it and hit OK.

This is what it should look like. If not, don’t @ me.

Step Four

Bask in the beauty of your creation. If you want to adjust something, double click the stroke in the Brush Window, make adjustments there.

Notice it bends beautifully at the corners. 🤤

It’s a hamburger-looking thing in a box. It will ONLY show up on selected strokes.

Step Five

To troubleshoot a flipped orientation start with selecting the stroke affected.

Under the Brushes Window, click the button seen in the image to the left. It’s called “Options for Selected Object” if you hover your mouse over it.

Click on Preview, then FLIP ACROSS. Or Flip Along. Whatever gets it to swap.

Step Six

Hit Preview then Flip Across. You should see the stroke correct itself.

This works on stroked objects and stroked paths alike.

Last Thoughts (Step Seven?)

You can do things with the stroke including dashed lines and adjusting the width with the Line Width tool, size the stroke (it defaults at the size of your rectangle croup, so either you need to scale the stroke below 1pt or make the initial object smaller).

You’re going to always end up with the shape you see in the top left, I don’t know why it does this and haven’t yet found a good solution for it yet. Here’s some solutions and how I accomplished them.

You will need to manipulate your closed shapes, or potentially mirror and/or strong-arm the paths with duplicates to get the look you want.

Good luck.




Designer, Illustrator, Tea Drinker @katiadesignsthings on IG