USING THE DRAWING TOOLS

Though the Shape and Line tools often give many drawing objects a head start, most vector artwork is the product of heavy Pencil and Pen tool use. If the Pencil tool is freedom, the Pen is precision. Both tools can create open or closed vector paths, and each has functions for modifying existing paths.

Pencil Tool

As its name implies, drawing with the Pencil tool is as familiar as drawing with a pencil. With this tool selected, simply click and drag; wherever the cursor travels, so does the path. Illustrator automatically creates an anchor point every time the path changes direction. This makes drawing easy, but it also tends to make overly complicated paths, with too many direction changes. See the "Modifying Paths" section for the tools and techniques of cleaning up and massaging paths.

Let's try a quick drawing with the Pencil tool:

Select the Pencil tool from the Tools palette.

Click and drag to draw a path in the shape of an apple (see Figure 16.11).

Figure 16.11. A rough apple sketch drawn with the Pencil tool.

Close the path by dragging back to the start point.

The Pencil tool can not only draw paths but modify existing ones as well. Try this exercise to take a bite out of the apple:

Select the apple path by clicking on it with the Selection tool.

With the Pencil tool, click directly on an anchor point in the apple path and drag a roughly round shape inside the apple.

End the path on another existing anchor point on the apple path. The bite should be subtracted from the apple path (see Figure 16.12); if not, you probably missed the anchor point either at the beginning of the bite path or its end. Undo and try again.

Figure 16.12. The apple with a bite out of it courtesy of the Pencil tool.

Choosing Undo from the Edit menu or with the keyboard shortcut Ctrl+Z (Windows users) or -Z (Mac users) will undo the entire Pencil drawing; with the Pen tool it will undo only the last anchor point created.

With an electronic stylus and tablet, Pencil tool drawing is far easier than with a mouse or trackball. Mastering the Pencil tool with such an input device is easy because it becomes just like drawing with a real pencil on paperyou even have the optional luxury of varying stroke weight according to the angle of the stylus or the pressure exerted on the tablet.

Pen Tool

Wacom (http://www.wacom.com) is the leading manufacturer of styluses and tablets, though Aiptek (http://www.aiptek.com) and other competitors exist.

With the Pencil tool, the focus is on the shape; draw the path segments, and Illustrator automatically creates the anchor points to define them. This behavior facilitates freedom and rapid sketching of an idea. The Pen, the precision drawing tool, is the Pencil's opposite: Draw the anchor points and Illustrator automatically connects them with path segments.

Each click with the Pen tool creates an anchor point (or end point). Each click subsequent to the first connects the points with path segments. Try this exercise:

1.	Ctrl-click (Windows users or -click (Mac users) to deselect the previous path and prepare to draw a new one.
2.	Click and release once on the artboard with the Pen tool. It should result in an end point.
3.	A few inches away, roughly parallel with the first end point, click again, which connects the two points with a straight path segment.
4.	Directly below the second anchor point, at a distance of a few inches, click a third time.
5.	Now click a fourth time to create an anchor point beneath the first end point and parallel to the third.
6.	Click once more on the first point to close the path. As you hover over it, a small circle appears beside the Pen cursor. This circle indicates that you are closing a path. You should now have a rectangle.

In the rectangle drawing there are four corner points, anchor points defining and attached to independently angled (often straight) path segments. More often than corner points, drawings require smooth points with curvature. It's important to note that, though the path segments display the curvature, anchor points control the curvature and direction of path segments leading into and out from them.

Hold the Shift key while clicking to make a new anchor point to limit its location to an increment of 45° relative to the previous anchor point.

Smooth points are created by clicking to create the anchor point (or end point) and dragging to introduce curvature. They are easily identified by the presence of direction lines or curve handles emanating from them (see Figure 16.13).

Figure 16.13. After clicking and dragging, direction lines appear.

Try this exercise:

1.	Ctrl-click (Windows users) or -click (Mac users) to deselect the previous path and prepare to draw a new one.
2.	With the Pen tool, click and hold on the artboard.
3.	Drag the mouse upward a bit, away from the end point to introduce curvature. Direction lines should appear beneath the cursor, which becomes a black arrow.
4.	Drag the direction line upward and to the right an inch or two at approximately a 45° angle.
5.	A few inches to the right, click and release to create the second end point. You should now have a curved path segment (see Figure 16.14). Figure 16.14. A simple arc path segment.

Each anchor point has its own curvature settings, making both ends of a path segment malleable. Try creating an S-curve:

1.	Ctrl-click (Windows users) or -click (Mac users) to deselect the previous path and prepare to draw a new one.
2.	With the Pen tool, click and hold on the artboard.
3.	Drag the mouse upward and to the left, an inch or two at approximately a 45° angle.
4.	A few inches to the right, create the second end point by clicking, but don't release.
5.	Drag the second end point up and to the left, trying to mirror the angle and distance as in step 3. Notice how the path segment changes from a simple arc to a smoothly sloping S-shape (see Figure 16.15). Figure 16.15. A simple S-curve made from two points.

Smooth points have inheritance, that is, the curvature assigned to one point automatically applies to the next (but not the one following). So, clicking and dragging to create a curved path segment on one smooth point automatically carries over to the next anchor point, following the path segment through and converting this second point automatically to a smooth point. This is what occurred in the exercises you've done so far. To illustrate the point, try this:

1.	Ctrl-click (Windows users) or -click (Mac users) to deselect the previous path and prepare to draw a new one.
2.	With the Pen tool, click and release on the artboard, creating a corner point.
3.	A small distance away, click and hold to create another point and introduce curvature.
4.	Click and release to create a third point, which inherits the curvature from the second.

Curvature inheritance is a convenient way of making complex pathsmaking the two to four arcs of an ellipse, for example, requires little more than half the effort. When inheritance is not desired, however, there is an easy way to eliminate it. After creating one curve, but before clicking to establish the next anchor point, click once on the last smooth point. This action converts the anchor point from a smooth to a corner point, creating independent curvature and angling to the path segments on either side of that point. Now the next anchor point may be defined exclusive of the previous; click and release to create a corner point and straight path segment, or click and drag to create a smooth point with independent curvature.

Let's try creating independent points:

1.	Ctrl-click (Windows users) or -click (Mac users) to deselect the previous path and prepare to draw a new one.
2.	With the Pen tool, click and release on the artboard, creating a corner point.
3.	A small distance away, click and hold to create a smooth point. The path segment should be curved.
4.	Move the cursor back over this second point, which shows a small, inverted V beneath the Pen tool cursor, denoting that it is acting as the Convert Anchor Point tool (see the section titled "Adjusting and Converting Anchor Points," later in this chapter).
5.	Click on the second point; one of the direction handles disappears.
6.	Click and drag to create a third pointan independent smooth pointa few inches away. Inheritance has been canceled, and this new point is completely independent of the prior points and path segments.

The more points in a curve, the more complicated it becomes when working with changes and when printing. Many beginners draw complex paths as a series of corner points or very shallow smooth points, clicking and creating a new anchor point at each minor course or curvature change. Exploit the curvature of smooth points to reduce the overall number of points, the complexity of the path, and the likelihood of unsightly bumps that can be caused by anchor points at awkward places in a curve (see Figure 16.16).

Figure 16.16. In the main curve an extraneous anchor point is causing an unwanted bump (left). By eliminating this point and adjusting the direction handles of the smooth points on either side of it, the curve renders smoothly (right).