Paint with Photoshop CC's Brush Tool
You control where the Brush tool works by selecting a brush tip of a particular size, shape, and hardness (the fuzziness, or lack thereof, along the edges of a round brush tip). Remember, too, that you can use the Brush and other painting tools to create subtle changes in existing colors.
By selecting an appropriate blending mode and opacity, you can mix the painting color into the existing colors in your image. Make these basic decisions from the Options bar, shown for the Brush tool.
As you see in the figure, the Options bar gives you access to a miniature Brush panel, from which you can pick a brush tip, change its size, orientation, roundness (some brush tips), and adjust the hardness of the brush’s edges . (Only round brush tips use the Hardness adjustment in the Options bar.)
The five sample lines to the right show Hardness, from 0% to 100% in 25% increments, all using a 40-pixel brush. The Brush tool can use any brush tip that you have in the Brush panel — and you can customize the brush tip in a variety of ways.
You’re actually ready to paint in Photoshop already! Select a foreground color, select the brush size that you want, decide how hard or fuzzy the edges should be, change the blending mode and opacity (if desired), and drag the tool in your image. (And, perhaps best of all, no turpentine needed for cleaning up — just switch tools in the Toolbox.)
As you work with the brush-using tools, always remember that the selected brush tip is applied as a series of individual impressions, called instances. Consider an instance to be a single impression of the brush tip, like tapping a pen once on a piece of paper — it leaves a single dot.
Take a look at the outer borders in this figure. Changing the brush tip’s Spacing value (in the main Brush panel, opened through Photoshop's Window menu) shows how instances appear. In the upper left, the spacing is set to the default 25% and a continuous line results.
To the upper right, Spacing is set to 67%, and the individual brush tip instances are visible as overlapping circles. To the lower left, Spacing is set to 133% — this is a setting that you might use for a dotted or dashed line — and each brush tip instance is visible individually.
If you know you have the cursor set to show the brush tip, but you’re seeing the tiny little crosshairs instead, check the Caps Lock key on your keyboard. Caps Lock toggles between precise and brush-size cursors for the brush-using tools.
When you change the Brush tool’s Opacity setting on the Options bar, you change the appearance of the stroke as a whole. Changing the Flow setting (also on the Options bar), on the other hand, changes the amount of color applied with each instance of the brush tip.
When the flow is reduced and the spacing is set to less than 100%, the overlapping area of each brush instance appears darker (or lighter when painting with, for example, white on black).
One last item in the Options bar for the Brush tool deserves a quick look. To the right of the Flow field is the Airbrush button. When the Airbrush is on (the button turns dark), the Flow value takes on more meaning.
As you paint with the Brush in Airbrush mode with a reduced Flow setting, pausing the cursor with the mouse button down allows color to build up (become more opaque) as if you were using a real airbrush. You can use the Airbrush both as a traditional airbrush artist and to simulate spray paint. You can see both in this figure.
If your computer has a processor and video card that support OpenGL drawing, you can rotate the image on screen for easier painting — not rotate the canvas, but rotate the on-screen image! This can be great for fine-tuning a layer mask or doing other delicate painting tasks.
Using the Rotate View tool (nested with the Hand tool) permits you to arrange the artwork for your most comfortable painting stroke. While dragging the Rotate View tool, an on-screen compass's red arrow always orients you to the top of the image. When you want the image oriented back to the top, simply double-click on the Rotate View tool icon in the Tool panel.