How to Create Paths with the Pen Tool in Photoshop CS6
Unlike the other selection tools in Photoshop CS6, the Pen tool doesn’t initially produce a selection marquee. When you select the Pen tool and start clicking and dragging around your image, you create a path. Paths have three types of components — anchor points, straight segments, and curved segments.
Curved paths are Bézier paths (after Pierre Bézier — who, in the 1970s, invented the equation used for CAD CAM programs). They’re based on a mathematical cubic equation in which the path is controlled by direction lines that end in direction points (often referred to as handles). The length and angle of direction lines control the pitch and angle of the Bézier curve.
The following list introduces the different kinds of anchor points that Photoshop puts at your disposal. You can use some or all of these anchor points in a single path:
A true corner point: Has no direction lines. Use corner points when you’re selecting objects that have straight sides, such as stairs or barns.
A smooth point: Has two direction lines pointing in opposite directions that are dependent on one another. Use smooth points when selecting objects that have alternating curves, such as a sea of rolling waves.
A cusp point: Has two direction lines that are independent of one another. Use cusp points when you’re selecting an object that has curves going the same direction, such as the petals on a daisy.
A point between a straight segment and a curve: A corner point that has only one direction line.
After you create a Bézier path, you can then edit the path by moving, adding, deleting, or converting anchor points and by manipulating the direction lines. You can also transform paths by choosing Edit→Transform Paths. When you transform a path, you can scale, rotate, skew, distort, change the perspective of, or warp the path.
The path hovers over the image in its own space. You control the path via the Paths panel, where you can save it, duplicate it, stroke it with color (apply color to the edge only), fill it with color or a pattern, and (most importantly) load it as a selection.
It’s “most important” because often you painstakingly create a path as a means to an accurate selection marquee. You may also use the path as a shape or as a vector mask at other times: to hide a part of a layer or part of an image.