The Lasso Tools

The Lasso tool allows you to select intermittent portions of an image by tracing them in a freehand style. Sounds great, right? It is. Except for one major flaw—the tool is extremely difficult to control. Fortunately, Photoshop also includes Magnetic and Polygonal versions of the Lasso that can help guide your free-form selections. But the truth is that all three lasso tools are hard to trace with. You’ll want to avoid making large detailed selections with the Lasso. It is best used for modifying selections or for selecting small areas that need to be retouched. If you’re new to the lasso tools, my recommendation is to start out by using them to select simple shapes—not detailed objects containing lots of intricate bends and curves. The simpler the shape you’re trying to select, the easier it will be to trace with one of the lassos. Keep in mind also that the more you draw with the lasso tools, the easier it will get. After a while, detailed selections will not seem as hard.

Lasso with a Graphics Pen and Tablet
If drawing freehand is your specialty, you might want to try using a graphics pen and tablet. Doing so can make tracing with the lasso tools much easier.

The Lasso Tool
In my experience, the Lasso is a much better tool for fine-tuning existing selections than for drawing new ones (a topic we’ll explore further in “Modifying and Transforming Selections” later in this chapter). However, if you have a steady hand and an incredible amount of patience, you can use the Lasso to make entire selections. You can access the Lasso tool by clicking and holding the currently visible Lasso tool icon in the Tools palette and selecting Lasso Tool from the pop-up menu that appears. You can also toggle between the Lasso, Magnetic Lasso, and Polygonal Lasso tools by pressing Shift+L. To make a normal selection with the Lasso, check the Options palette and make sure Anti-alias is selected and the Feather amount is set to 0px.

To make a free-form selection with the Lasso tool, click to create a starting point and proceed to trace around the image. Now, here’s the tricky part: You must keep the mouse button pressed at all times while making the selection. If you release the mouse button early, Photoshop assumes that you have finished tracing and closes the selection path automatically.

If you zoom in on the image before you begin tracing, you can make a much more precise selection. As you trace, click and hold the spacebar to temporarily access the Hand tool and navigate around the image. This way, you don’t have to let go of the mouse button and risk closing your selection early.

How to Zoom While You Select
As you trace with the traditional Lasso tool, you can zoom in or out on the image by holding the F/Ctrl key while pressing the plus (+) or minus (–) keyboard shortcuts. Just be careful not to let up on the mouse button!

The Magnetic Lasso Tool
The Magnetic Lasso tool offers you much more control for selecting entire objects than the traditional Lasso does. This version of the lasso automatically senses the edges of an object as you trace, even if the photograph contains low contrast and varied background colors. Because of this, the Magnetic Lasso tool is actually a much better tool for selecting the flower than the Lasso. You can access the Magnetic Lasso tool by clicking and holding the currently visible Lasso tool icon in the Tools palette and selecting Magnetic Lasso Tool from the pop-up menu that appears. You can also toggle between the Lasso, Magnetic Lasso, and Polygonal Lasso tools by pressing Shift+L.

Toggle between Tools in a Set
Another way to toggle between tools in a set, such as the lasso or marquee tools, is to Option/Alt+click the currently visible tool icon in the Tools palette.

To make a normal selection with the Magnetic Lasso, check the Options palette to make sure Anti-alias is selected and the Feather amount is set to 0px. Then click to create a starting point and proceed to trace around the edge of the image. The great thing about the Magnetic Lasso is that you do not need to keep the mouse button pressed as you trace—all you need to do is click once and move the mouse. Depending on your Options palette settings and where the mouse is placed, Photoshop determines where the edge is and makes the selection for you. As you trace, the tool locks the line segments in place by automatically adding square anchor points to the selection path.

The additional Options palette settings allow you even greater control over the tool. The most significant of these is the Width option, which lets you set how close to the edge of the object your cursor needs to be for the tool to recognize it. Larger values allow you to be less precise when tracing. Smaller values are helpful when selecting detailed areas of an image.

Magnetic Lasso Width-Setting Shortcuts
You can increase or decrease Width settings by pressing the bracket keys as you trace with the Magnetic Lasso tool. Press ] to increase the Width value, and [ to decrease it.

The Edge Contrast option allows you to set a value for detecting the edges of an object. Lower values are better for detecting edges that are less defined; higher values are better for detecting well-defined edges. The Frequency option lets you set the rate at which the tool adds anchor points to the selection path. Higher Frequency values increase the number of anchor points added to the selection path as you trace.

Here are some additional tips for selecting with the Magnetic Lasso tool:
- If your selection path strays from the edge of the object, trace backward to fix it. Tracing backward will not erase anchor points.
- Press Delete or Backspace to erase unwanted anchor points.
- Click to add anchor points manually as you trace.
- As you trace, Option/Alt+click to temporarily switch to the Polygonal Lasso tool for a straight-line segment. Click again to add an anchor point and switch back to the Magnetic Lasso.
- To close a selection path drawn with the Magnetic Lasso tool, double-click or press Return/Enter.

When used properly, the Magnetic Lasso can be a powerful tool for removing an object from its background, as evidenced by the flower. This flower is now ready to be saved as a transparent graphic and placed in a layout.

The Polygonal Lasso Tool
Although it’s not nearly as slick as the Magnetic Lasso, the Polygonal Lasso still offers you much more control than the traditional Lasso. It is designed to select objects by using nothing but straight-line segments. Because it prohibits you from selecting any curved areas, the types of objects you can select with it are severely limited. However, despite that limitation, there’s still a lot you can select by using the Polygonal Lasso.

To access the Polygonal Lasso tool, click and hold the currently visible Lasso tool icon in the Tools palette and select Polygonal Lasso Tool from the pop-up menu that appears. You can also toggle between the Lasso, Magnetic Lasso, and Polygonal Lasso tools by pressing Shift+L.

To make a normal selection with the Polygonal Lasso, examine the Options palette to make sure Anti-alias is selected and the Feather amount is set to 0px. Click once to create a starting line segment and proceed to trace around the image. You do not need to hold the mouse button down as you trace. Each additional click creates a connecting, straight-line segment.

Here are some additional tips for selecting with the Polygonal Lasso tool:
- Press Delete or Backspace to erase unwanted angles.
- Press and hold the Shift key as you draw to constrain the angle of the line segments to the nearest increment of 45°.
- To close a selection path drawn with the Polygonal Lasso tool, double-click or press
Return/Enter. You can also close the path by hovering over the starting point and clicking.