Commonly used in diplomas and certificates to prevent forged copies, Guilloche is a intricate and repetitive pattern used for decoration or security purposes. This type of patterns may seem very complicated to make, but they are actually very easy to create in Illustrator if you use the correct tools. So today, I will show you how easily you can make your own Guilloche Pattern in Illustrator by making a Guilloche brush and using it to make those intricate patterns.
Open Illustrator and make a new file at any size you want. In this case, I will setup mine at 1800 x 1200 px.
Select the Line Segment Tool (\) and click once over the artboard. In the Line Segment Tool Options, set the Lenght to about 500 px and click OK.
Hold the Alt key, click on the line and the hold the Shift key at the same time and drag the line down about 10 px to make a copy of it.
Next, press Ctrl+D between 25 and 30 times to make multiple copies of the line.
Using the Pen Tool (P) or the Pencil Tool (N) draw a simple section of the shape that you want to use on your guilloche pattern. Curvy lines works better for this type of patterns, but you are free to make any kind of shape that you want.
Just to be sure that your shape is on top of the lines, go to Object > Arrange > Bring to Front.
Next, select all the artboard objects (Ctrl+A) and go to Object > Envelope Distort > Make with Top Object.
Go to Window > Brushes to open the Brushes Panel.
Drag the artboard elements into the Brushes Panel, select "Pattern Brush" in the New Brush window and click OK.
Apply the following settings in the Pattern Brush Options window and click OK. Be sure to select "Auto-Between" from the thumbnail dropdown menu on the Outer and Inner Corner Tile (first and third thumbnail). As you may see, the new Guilloche brush shows on the Brushes Panel.
To use the Guilloche Pattern, select the Ellipse Tool (L) and draw a circle.
With the Circle selected, simply click on the Guilloche brush we just did.
If you scale up the circle, you may see your Guilloche pattern change according to the shape size.
Now that you know how to make your own Guilloche Pattern, you can try many different shapes, colors (by changing the stroke color in the Swatches Panel) and even overlap different shapes to make a more intricate pattern.