This spring, Adobe introduced new tools for digital painting in Photoshop CS5. The new Mixer Brush goes a long way towards creating a realistic simulation of how paints mix and blend with each other on a canvas and with textures on the document canvas. The other side of the equation is the new Bristle Tips, which simulate the physics of real paintbrushes. While it is impossible to cover every facet of these impressive tools in the span of a single article, I can focus on how to quickly get started with these tools, so that you can begin experimenting with your own photos.
One benefit of using the new Mixer Brush workflow is that it can breathe new life into shots we may have otherwise discarded. Good composition, good light, but maybe the exposure was off or the focus too soft in spots to be recovered. Those photos make an excellent foundation for digital paintings in Photoshop CS5.
Bristle Tips Explained
Bristle Tips are a new kind of brush preset (designed primarily for use with the new Mixer Brush), and they reside in familiar locations, like the Brush Picker in the Options bar and in the Brush panel. When working with these tools, first set up the user interface for a painting workflow. Click on the Painting button to open Photoshop’s default painting workspace.
Next select the Mixer Brush, grouped with the Brush tool, Pencil tool and Color Replacement tool (shortcut B or Shift-B to cycle through them). Then, from the Brush panel, click one of the icons that looks like a real paint brush (Figure 1), rather than the traditional brush outline. These are the Bristle Tips.
Once selected, the Brush panel displays the parameters for defining the look of a Brush Tips stroke (Bristle Qualities), as well as a preview of the brush stoke. Photoshop ships with two types of Bristle Tip to reflect the real-world options: brush tips with a rounded set of bristles and those with a flattened set of bristles. Both round and flat have five subtypes (found in the Shape pop-up menu): Point, Blunt Curve, Angle and Fan.
Figure 2 shows a simple brush stoke made with each, using a 40 pixel brush size. Customize these shapes by changing the Bristle Quality settings, which control things like the bristle density (Bristles slider), bristle length and thickness, and how flexible the bristles are (Stiffness). Watch the preview to see how the settings interact. As with other brushes, the Bristle Tip parameters can be customized and saved as a preset.
Preview Bristle Tips by clicking on the Bristle Brush Preview button at the bottom of the Brush panel (left-most icon). A small overlay will appear over the active document displaying an “artist’s eye view” of the brush being used. As you press the stylus to the tablet and begin to paint and tilt your brush, the preview will show the effect on the actual brush bristles (Figure 3). If you have a Wacom 6D Art Pen, this preview and the Bristle Tips will support brush rotation, as well. If you click the overlay, the preview orientation will change to give you different vantage points. Shift-clicking the overlay changes the preview from a line drawing style to a 3D rendered style.
The Mixer Brush Explained
With an understanding of how Bristle Tips differ from normal brush presets, let’s look at the other side of the equation. Essentially, the Mixer Brush treats pixels like real paint―as you paint over previous brush strokes you can blend colors on the fly and create new kinds of strokes that are neither symmetrical in shape nor uniform in their density like a typical Photoshop brush. In short, it is designed to work exactly like a paint brush loaded with a predetermined amount of paint as it glides across a canvas. Figure 4 provides a look at the Mixer Brush painting options.
The Load setting determines how much “digital paint” is present among the bristles and on the surface of the brush. The Load amount is controlled by the Load slider. The type of colors being loaded (or whether there is a load present) is controlled in one of three ways: 1) Clicking the Load button will automatically load the current color or mix after every brush stroke; 2) Leaving the Load button off and using the Load pop-up menu to manually load the brush; 3) Alt-clicking on a portion of the image. The last option uses two behaviors. If the Load Solid Colors Only option is checked in the pop-up, pressing Alt will provide an eyedropper to select a single color. If that option is turned off, pressing Alt over the document will sample the pixels around the cursor and place those colors as the load (Figure 5).
Note: It’s also a good idea to paint on a separate (empty) layer by taking advantage of the Sample All Layers setting in the Options Bar. This allows you to control the opacity and blend mode of the paint layer as well as clip adjustments to it without affecting the background photo.
Photoshop provides the ability to clean the Mixer Brush each time you pick up the stylus. After each stroke, click the Clean Brush button. Most of the time I use this feature in combination with no load or a very light load; this way when I paint over photos, each brush stroke is interacting with the pixels under the brush. For a more organic looking painting, leave Clean Brush off. Figure 6 shows one area of the photo painted with a load, a neighboring area with no load (otherwise similar settings), and the final area with a load and no cleaning.
The Wet setting describes how wet or dry the canvas and paint are. Like real paintings, the less dry the paint, the more it can be spread across the canvas, mixing with other colors and textures. The easiest way to use the Load, Wet settings (as well as the Mix setting―discussed next) in combination is to work with the Blending Brush Combinations pop-up menu (left of the Wet slider in the Options bar). Adobe created several combinations that can help you to relate the settings of the Mixer brush to working with a particular kind of paint you might be used to (such as oil paints). Most often I find the Moist presets (or slight variations) to be the most useful when painting over a photo, as it makes the process of maintaining the general outlines and details easier. Blending Brush Combinations menu options are shown in Figure 7.
This setting defines how readily the brush will mix the colors on the canvas to create new colors and blends. When using real paints, certain types mix to create new colors, while others tend to cover up underlying colors, depending on the mediums being used and other variables.
The Flow defines the amount of paint that’s being added to the canvas. The higher the value, the denser the paint will be, and the colors and details underneath will show through less.
Ultimately the best way to familiarize yourself with Photoshop’s new painting tools is to sit down for an hour or so and really experiment with the various Bristle Qualities and Wet – Load – Mix combinations (and even the Texture option from the Brush panel). As you do so, you will find combinations that suit your taste and style of painting, and which suit your images as well.