Photoshop Tutorial: Paths, Pen Tool & Bézier Curves

Adobe Photoshop CS-CS5 Painting Tutorials

Photoshop Paths | Airbrush/Brush Tool | Basic Painting | Layer Masks | Color Management

All Tutorial Text & Images - Copyright © 2011 KHI, Inc.

In Adobe Photoshop CS, drawing line-art can best be done via the Pen tool (P). The Pen tool is one of the most useful tools in the Photoshop tool palette, but it can also be one of the most frustrating tools to master for the Photoshop newcomer. Once you become comfortable with this powerful tool you will rarely use the Line tool.

The Pen tool can create straight lines by clicking point to point or by constraining its movement with the shift key. It can also create graceful bends, curves, and other PostScript shapes that are referred to as Bézier Curves (named after French mathematician and engineer Pierre Bézier). Note: The following hardware and software was used in this tutorial: Apple Mac Pro, a Wacom Intuos 6x8 drawing tablet and Adobe Photoshop CS3-CS5 with vector drawing capabilities.

Photoshop's Paths & Pen Tool Attributes

Photoshop's Pen tool has five attributes (A, B, C, D and E shown in Fig. 1). The main Pen tool A is the tool that you will use most of the time. The "Freeform" Pen tool B is used to draw paths freehand. I do not recommend using the Freeform tool due to the crude and imperfect paths it creates. The "Plus" Pen tool C is used to add new anchor points to a path. The "Minus" Pen tool D is used to remove existing anchor points from a path or stroke. Tools C and D are almost useless because you can easily access their features via keyboard commands while in the Pen tool A mode. Pen tool E can change a hard corner anchor point into a Bézier curve anchor point as well as change a Bézier curve anchor point back to a hard corner point.

To create a rasterized line with the pen tool you will use the "Stroke" command accessed from the Menu Bar (Fig. 2 Edit>Stroke). The term "Stroke" refers to the actual line that is created when you "Stroke" the path's selection. You should always "select" the path in order to stroke it (see next section). Stroking the path directly produces a flawed line. You can also "Fill" the selected area. The term "Fill" denotes the foreground or background color that will fill in the area within any shape that you create.

When creating line-art for technical illustration you would generally "stroke" the selection in a 100% solid solid black. The line thickness (or stroke weight) is controlled by the "Stroke" palette shown in Fig. 3. To stroke the line directly under the path you would use the "Center" setting under "Location".

Photoshop Paths & Actions Palettes

To Select the Path to be stroked, "Command>Click on the Path in the "Paths" palette shown in Fig. 4. The active path will be visible on the artboard and highlighted in the "Paths" palette. To save a path, double click it (it will be called "Work Path") and rename it in the "Save Path" dialogue box.

You can use the "Actions" palette window (Fig. 5) to create several commonly used "Stroke" commands. This will make stroking a Path a "one click" operation when the actions are set to the "Button Mode" shown in Fig. 5. Use the actions palette's "Record" mode to set all of the pre-defined parameters for the stroke effect.

Using Photoshop's Pen tool to create a straight line is as easy as clicking from point A to point B (Fig. 7). To constrain the line to a horizontal, vertical, or 45° diagonal line you would hold the shift key while you click point B. You will notice that the active anchor point is a solid box (point B) and the inactive anchor point (A) is an empty box.

Creating Bézier Curves & Drawing Paths with the Pen Tool

To create the arc shown in (Fig. 8) you would click and drag point A upward while holding the shift key to constrain the motion vertically. This will create a "Control Line" with a Control Handle." Next you will click point B dragging the Control Handle to the left. Holding the shift key will constrain the dragging motion in a horizontal plane.

Now we will distort the arc's shape (Fig. 9) by clicking on one of the Control Handles and dragging it toward the upper-right. The active anchor point (B) is solid and the inactive anchor point (A) is an empty box. When you release your dragging motion the new shape will appear. Technical Note: If the stoke is not active you can re-activate it while in the Pen tool mode by holding the Command key while clicking anywhere along the stroke.

We will now add a third anchor point (C) to our diagonal line in Fig. 10. By clicking this cursor along the path you will create a new anchor point. When we add a third anchor point to Fig. 11 you will see Control Lines and Handles appear (D). These new Control Lines and Handles assume the correct positioning to follow our arc as it was before this addition. Now we will drag Control Handle D downward and to the left Fig. 12. The Control Handle acts like a magnet, pulling the arc in the same direction as your dragging motion.

Technical Note: When you position the cursor over an active path while in the Pen mode a "plus" sign will appear next to the cursor. When you position the cursor over an existing anchor point while in the Pen mode, a "minus" sign will appear next to the cursor. If you click on the existing anchor point it will remove it from the path.

When you position the cursor over the last anchor point in an open path while in the Pen mode a "0" will appear next to the cursor (Fig. 13). This indicates that the path will be closed after clicking on anchor point B from anchor point A. Once the Path is closed you can make a "Selection" out of the it (Fig. 14) by "Command>Clicking on the Path in the "Paths" palette shown in Fig. 4 above. With the path selection made you would stroke the selection using the "Stroke" palette found in the menu bar. Fig. 15 shows a 1 pixel (1 px) stroke weight with 100% black.

Technical Note (Early versions of Photoshop): Remember that in earlier versions of Photoshop the line thickness is controlled by the "Stroke" palette shown in Fig. 3 above. To stroke the line directly under the path you would use the "Center" setting under the "Location" setting.

Photoshop CS4/CS5 and Later

It should be noted that current versions of Photoshop have a native "vector" path program built into their software that is similar to Adobe Illustrator Paths although there are subtle differences in tool behavior and keyboard commands. This totally eliminates the need to "stroke" a path selection although it is my belief that stroking a selection still creates the smoothest rasteized line - especially when the line is .25 points or thinner.

Although this is a very basic lesson in the use of the Photoshop's Pen tool and its ability to create shapes and curves, by using the techniques discussed in this tutorial there is no limit to the complexity of the shapes you can create.

Conclusion

The Acura NSX line art (below) was created entirely within Photoshop using only the "Stroke Selection" feature to stroke each path after it was created. This line art took approximately 210 hours to complete using the techniques described in this tutorial. To see how this line art was painted go to the advanced Creating Ghosted Illustrations tutorial.

Back to: Illustration Tutorials

Home| Automotive Illustration| Line Art Illustration| Car Stock Images| Illustration Tutorials

Copyright © 1996-2012 KHI, Inc. and AutomotiveIllustrations.com. All rights reserved.