Whether you are an image editor or an artist, there will be a moment where you need to use the Brush tool in Photoshop. In Photoshop and other image editing tools, the use of the Brush Tool is pretty similar to the physical paintbrush where you can use it to paint a certain area of your image. In Photoshop, the Brush Tool is adjustable. Before you use it, you can set the brush shape, size, color, opacity, angle, and so on. You can adjust the Brush Tool according to your needs.
Photoshop itself comes with a number of default brush shapes. You can enrich the brush shape options by installing new Photoshop brushes.
How to use the Brush Tool in Photoshop
By default, the Brush Tool is grouped with Pencil Tool, Color Replacement Tool, and Mixer Brush Tool. To start using the Brush Tool, click and hold the Brush Tool icon on the toolbox and select the Brush Tool then paint the area you want to paint. Or, you can also activate the Brush Tool by pressing the B key on the keyboard (more Photoshop shortcuts).

Adjusting the Brush Tool
As mentioned earlier, you can adjust the Brush Tool before start using it. Here are some key adjustments you might want to set.
- Color
To set the Brush Tool color, simply set the foreground color. This adjustment lies in the lower side of the Photoshop toolbox.

- Mode and opacity
With the Brush Tool selected, go to the options bar (beneath the menu bar). Set the mode on the Mode option and the opacity on the Opacity option.

- Brush shape, size, angle, and so on.
For more advanced adjustments, you can open the Brush Settings window by clicking the Brush Settings on the right panel or by clicking the Window menu and select Brushe Settings. As the Brush Settings window appears, you can set brush shape, size, angle, roundness, spacing, and tip shape.

All of the adjustment options on the Brush Settings window are clear enough except (maybe) the tip shape. A tip shape is some kind of a special effect applied to the Brush Tool. For instance, if you enable the Shape Dynamic tip shape, Photoshop will use a different brush size on each click as you the Brush tool. There are 12 tip shapes you can use.
How to Get More Brush Shapes in Photoshop
The default brush shapes offered by Photoshop are limited enough. To enrich your brush collections, you can install new ones. Photoshop itself offers a number of brushes you can download for free. To view them, open the Brushes window (Window -> Brushes). Click the flyout menu and select Get More Brushes.

Alternatively, you can also download a Photoshop brush from third-party websites.
Photoshop uses the .ARB file extension for its brushes. You can simply copy the ARB file of the brush you want to install to the “Brushes” folder with the following path:
C:\Program Files\Adobe\Adobe Photoshop Version\Presets\Brushes
If you use Mac, the “Brushes” folder usually lies on Users > Library > Application Support > Adobe.