
Have you ever wanted to add a simple wave pattern as a background to your design or a graphic to use with your web software and were disappointed with the pre-made patterns in Illustrator and Photoshop?
The limited selection and inability to customize those cookie cutter patterns choked my creativity. So, I attempted to create my own wave pattern. Armed with the confidence of creating successful seamless patterns in the past, I thought ‘How hard can this be?’
I thought wrong...

I had approached this in the usual way of starting a seamless pattern. I started with a 1000 x 1000 px document in Illustrator, and then used the Pen tool, and Transform Effects options. I soon discovered the difficulty in predicting a consistent wave and ended up with a choppy unpredictable pattern. In order to get this wave to cooperate I needed to be more intentional with my math.

After a some trial and error with the Zig Zag effect, I tested the pattern and there it was. A seamless wave pattern with the flexibility to customize. I'd like to show you how to do it in a few easy steps.
Note: This tutorial is recommended for intermediate Illustrator users. I used Adobe Illustrator CC 2019 and a Mac for this article, some keyboard keys and tools may be different depending on the computer you use or the version of of Illustrator.
Troubleshooting Tips are at the end of this article for some of the problems I encountered while making this pattern, you might encounter different problems that I'm unaware of. Leave a message for Wittner Design on the contact page and I'll work through the problem and add it to Troubleshooting.

STEP 1: Creating the Document.
Create a New document, use the settings in the image above then click Create. If you have a different color mode than RGB you can find it in More Settings, click on More Settings to open up its panel and find Color Mode, click on it and in the drop down menu click RGB then click Create Document.

STEP 2: Creating and Aligning the Beginning line.
Make sure you have No Fill, and you have a black Stroke. Click on the Pen Tool and create a 1 px line straight across the width of the artboard, while pressing the Shift key to constrain the angle.
Check the length of the line with the Transform panel, ( which can be accessed on the top toolbar, or right side toolbar, or by clicking on Window to get it from the drop down menu) if needed, change your line Width to 1000 px.
Keep the line selected and click on Align. Select Align to Artboard then click on Align Horizontal Center and Vertical Align Center. Your line should be a width of 1000 px and perfectly centered at the top of your artboard.

STEP 3: Making Waves.
We'll make a wave out of this line with the Distort & Transform Effect. Keeping your line selected, click on Effect then go to Distort & Transform and click on Zig Zag.

The Zig Zag panel opens. Use the settings I've entered in the image above. Select Smooth for a round wave or Corner for a pointy wave, select Preview to see your changes, then click Ok.
Note: The important number to enter is in Ridges per Segment.
You might ask why or you might want the short answer.
Warning: Long Answer ahead followed by Short Answer.
Long Answer: Ridges are the waves. Your 1000 px line is made up of one segment and it’s on an Artboard 1000 px wide. The number of ridges (waves) per this one segment line must be a number that fits into these constraints. This provides for both ends of the line to meet seamlessly when the pattern is made. I came up with any two digit number that ends in 9, or just 9
(I didn't go as far to experiment with 3 digit numbers). The Short Answer: Use one of these numbers 9, 19, 29, 39, and so on, use whichever number meets your design needs and ends with 9.

STEP 4:
Duplicating the Wave.
Now that you have your wave, next we'll duplicate the wave so it fills the Artboard. Click on Effect then go to Distort & Transform, click on Transform.

The Transform Effect panel opens, (since the wave height is 10 px the Vertical Move should be at least 10 px unless you unless want your waves to overlap). Continue to enter the settings in the above image. Select Preview to see the copied waves, Click Ok. And there it is.
Next let’s make this into a New Pattern Swatch and take it for a test drive.

Step 5:
Making a New Pattern Swatch.
We'll drag your waves into the Swatches panel to make a New Pattern Swatch.
Create 1000 px by 1000 px square with the Rectangle tool with no Fill and no Stroke.
Important: There's a good chance that this new square 'adopted' the Effects on this layer, go to the Appearances panel and check, see Troubleshooting at the end of this article to for instructions and a visual on how to find and get rid of the unwanted Effects.

This new square needs to be underneath and aligned with the waves. Keep the new square selected and with the Selection tool, Right click on the Artboard and a menu will come up, go to Arrange and click on Send to Back.

Next Align the new square to the Artboard by clicking on Align, make sure Align to Artboard is selected, select Horizontal Align Center and Vertical Align Top as you did to align your beginning line in Step: 2.

Open the Swatches panel, select both your waves and your new 'invisible' square together and drag them onto the Swatches panel. A plus sign should appear as your selection enters the Swatches panel.
A New Pattern Swatch is created. Now it’s ready to test.

The Test Drive:
To Make sure the pattern is seamless, we'll make a rectangle and fill it with the New Pattern Swatch.
Make a new layer to put the 'test' rectangle on. Zoom out to give yourself some room and Drag out a Rectangle with the Rectangle tool
(any size rectangle is good, in fact, the less square it is the better it is to test the pattern).
Fill the new rectangle with white then Copy it by pressing Command C, paste it on the front of the rectangle by pressing Command F. Fill the top rectangle copy with your New Pattern Swatch. It should be seamless and look fabulous. If not see Troubleshooting fixes at the end of the article.
