How to Select Straight Lines with the Polygonal Lasso Tool in Photoshop CS6

By Barbara Obermeier

Whereas the regular Lasso tool in Photoshop CS6 is great for selecting undulating, curvy elements, the Polygonal Lasso tool shines when it comes to the more regimented, straight-sided subjects, such as city skylines, buildings, and stairways.

Unlike the regular Lasso tool, the Polygonal Lasso tool has rubber band-like qualities, and instead of dragging, you click and release the mouse button at the corners of the object that you’re selecting. It’s like digital connect-the-dots. (Bonus: Less manual dexterity required.)

The following steps show you how to select with the Polygonal Lasso tool:

  1. Select the Polygonal Lasso tool in the Tools panel.

    You can also use the keyboard shortcut. Press the L key and then press Shift+L until you get the Polygonal Lasso tool. It looks like the regular Lasso tool, but it has straight sides.

  2. With the Polygonal Lasso tool selected, click to establish the beginning of the first line of your selection.

    A corner is always a good place to start.

  3. Move the mouse and click at the next corner of the object. Then, continue clicking at the various corners of your object.

    The line stretches out from each corner that you click, like a rubber band.

  4. To close your selection, return to the first point that you clicked and click one last time.

    When you place your cursor over the starting point, a small circle appears next to your cursor, a sure sign that you’re at the right place for closing the selection. A selection marquee that matches your Polygonal Lasso line appears.

    [Credit: ©iStockphoto.com/HerrBullermann Image #7510581]
    Credit: ©iStockphoto.com/HerrBullermann Image #7510581

Which tool do you use if you have an object with both curves and straight sides? You can have two, two, two tools in one! Hold down the Alt (Option on the Mac) key to have the Polygonal Lasso tool temporarily transform into the regular Lasso tool. Then, click and drag to select the curves. Release the Alt (Option) key to return to the Polygonal Lasso tool. This trick works with the other Lasso tools, as well.