The range of effects you can create using Propeller are pretty much unlimited. Although the plugin doesn't ship with all that many brushes and patterns (108 brushes and 28 patterns), you can use any image of your own to paint with. Propeller can automatically colorize it to match one of the existing color palettes, or you can use the original color from the image. Propeller will allow you to modify the image just as you would modify any of the preset brushes, and it will allow for the same sort of tracking, pressure sensitivity, etc. that the presets have.

Tool control
When you first look at the Propeller interface, you see a very simple toolbar consisting of traditional paintbrush, eraser, color selector, magnifying glass and hand tools. To start working, you just select the paintbrush tools and apply your strokes. This is called ease of use.

For functionality, this program—er, plugin—offers a degree of control that's entirely uncommon in Photoshop filters.

To begin with, you have three primary tabs that determine how your stroke will look: Brush, Color and Pattern. Under each tab, you get a pulldown menu of categories containing various sets of brushes, color palettes and patterns. You can even create your own categories and add your favorite brushes (or patterns) or your own brushes (or patterns) to the collections. You can also modify color palettes by adding to them and then saving them as separate sets.

The Brush and Pattern palettes in Propeller

Each brush you can select includes a default patterns and color, but you can swap out colors and patterns as you see fit.

But these are only the beginning. You can also interactively control the stroke, effect and dynamics of each brush. Stroke controls include opacity, size, sweep and angle. Opacity, size and sweep and also be assigned ranges, and angle can be set to "constant" or "track." (Ranges come into play in Propeller's Dynamics engine, detailed below.)