Making your own vector brushes
Illustrator may already come with a set of watercolor brushes, but they're pretty limited and you often need some custom ones to give your designs a unique touch or even to make an entire drawing. Today, learn how to make your own Illustrator Watercolor Brushes starting with your own watercolor strokes!
But before we start, something to have in mind when you are about to make vector brushes is to pick the right color to paint your strokes, a color that is suitable to adjust the grays and give them more or less contrast depending on the effect you want to give to your brush. A good color to make digital brushes (if not the best) is the blue (not too light or too dark). If you already have your brush strokes painted, let’s get started.
Open your scanned brush stroke image in Photoshop.
Go to Image > Adjustments > Desaturate.
Go to Image > Adjustments > Levels. In the Levels panel, adjust the levels in a way that you can see all the different gray areas of your stroke with a medium contrast, but still visible enough. In this case, I’ve set the Shadow Input Level to 10, the Midtone Input Level to 0,75, the Highlight Input Levels to 250 and the Shadow Output Levels to 15.
Go to Select > All and then to Edit > Copy.
Open Illustrator, make a new file at any size you want and then go to Edit > Paste.
With the Brush Image selected, go to Window > Image Trace.
In the Image Trace Panel, apply the following values and click the “Trace” button.
In the top toolbar, click the “Expand” button.
With the expanded shape selected, go to Window > Brushes. Click the Menu icon and select “New Brush” from the dropdown menu.
In the New Brush window, select “Art Brush” and click OK.
In the Art Brush window, give the new brush a name, apply the following settings and click OK.
Now you can see your new brush in the Brushes Panel.
Now simply draw a line (or any other shape) and with the line still selected, click on the Watercolor Brush to apply it.
If you want to change the color of the new brush, simply change the Stroke Color in the Swatches Panel.
Finally, if you wish to change the size, simply increase/decrease the Stroke Weight in the Stroke Panel.