illustrator techniques: defining a custom pattern brush, take-2

It came to my attention that I breezed by an important point in the tutorial on creating a custom pattern brush or frieze. The online Illustrator manual apparently doesn’t have a good overview of complex pattern brushes either. It’s important because it’s a potential pitfall when it comes to creating the single instance of the border design. So, here is a better method (and a more complete explanation) that works with a wider variety of drawing methods.

Start by drawing at least 3 replications of the design that you want to have repeated in the brush pattern. Note: make sure all objects are on the same layer.

Draw a box with no fill and no border and position it so that it defines exactly one instance of the pattern design:

This box should be the last object drawn or, if not, should be arranged in front (Object > Arrange > Bring to Front).

Select all of the pattern elements and the box (Select > All).

Create a clipping mask defined by the box (Object > Clipping Mask > Make)

This will result in one instance of the pattern design:

Next, make sure the mask contents are editable (Object > Clipping Mask > Edit Contents). The entire pattern will be selected, though those objects outside the mask will appear outlined:

In most cases you will need to Expand Appearance to divide strokes and fills into separate, editable objects (Object > Expand…) If this menu selection is not available it may mean that you already have discrete objects, though drawings consisting of both fills and strokes will require expansion.

This will bring up the Expand dialogue box. Choose both Fill and Stroke.

Note that the strokes now appear to be filled objects.

The next few steps are important and failure to do them is usually the reason for an error when it comes time to create the pattern brush. Check to see if anything needs to be Ungrouped (Object > Ungroup). If not, the menu option will be greyed-out and it is safe to continue. Otherwise, choose Ungroup and repeat, if necessary, until the option is greyed-out.

Then make sure the only the mask is editable (Object > Clipping Mask > Edit Mask).

After this, it is again important to click inside the masked instance of the design to select it, as opposed to the mask itself. Simply click once in the center of your design.

Next Divide the paths (Effect > Pathfinder > Divide):

Now, create a new pattern brush in the Brush panel (A) and, in the New Brush dialogue box, specify New Pattern Brush (B).

If all goes well, you should next see the Pattern Brush Options dialogue box. If you get an error message, the most likely cause is the contents of the mask were not expanded fully or they were not fully ungrouped. Undo repeatedly until you get back to before the mask was defined and try again. Depending on the intricacy of the design and the way it was constructed, you may need to choose (Object > ) Expand Appearance, instead if Expand… or it could be as simple as ensuring that you have clicked on the contents of the mask after making it editable.

Once you have successfully gotten to the Pattern Brush Options dialogue box, give the brush a name and the pattern instance should appear in the small preview pane indicating a “side tile” (as opposed to a corner).

Test the brush by drawing a line and applying the pattern brush to it:

The design should appear seamless, with no gaps or mismatches. Otherwise, go back and redraw the box to define the mask.


One Response to “illustrator techniques: defining a custom pattern brush, take-2”

  • Zachary Guidry Says:

    So, you are using Pathfinder->Divide to remove the clipping path. I had a hard time figuring that one out – maybe differences in Illustrator versions. At any rate, using a clipping path is allowed, but slows down Illustrator and causes out of memory errors. Get rid of the clipping mask!

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