Quick Mask is an intuitive way of selecting complex image areas using Photoshop's paint tools to define the selection area. The area is painted in as a mask, and you can erase or add to the mask to define the exact area you want to select. After you define the area, you exit Quick Mask to select the area. When you use Quick Mask with Photoshop's other painting tools (such as the Paintbrush tool), you can literally paint a mask or selection using the actual image as a guideline. In fact, you won't need to worry about staying within the lines because you can easily reverse the painting by switching the color you're painting with.
Open the File
Choose File, Open to launch the desired file.
Make a Basic Selection
Although you can start the selection process with Quick Mask, I find it's easier to make an initial selection first, just to set up a relationship between the mask and the rest of the image. Use any of Photoshop's selection tools and select the general area you want to define. Here, I used the Magic Wand tool to select a portion of the statue's back.
Set Quick Mask Options
Double-click the Quick Mask button in the toolbox to launch the Quick Mask Options dialog box. Select Masked Areas or Selected Areas to specify whether the mask represents the selection or the background (that is, whether you're covering or uncovering as you paint the mask). The default mask color is red, but you can click the color swatch and select another color. The selection you made in Step 2 reflects these settings as you make them. When everything looks good, click OK.
Draw or Paint the Selection
Use the Photoshop paint tools to fine-tune the mask. See Part 8, "Drawing, Painting, and Filling with Color," for details. You can choose smaller or larger brushes or zoom in to follow the lines of your image more closely. As you'll see in the next step, you also can easily erase any areas where you painted outside the lines.
Erase Unwanted Areas
Select the Erase tool and erase the mask to reduce the selection area as necessary. If the eraser adds mask instead of deleting it, select Edit, Undo and change the foreground color to white.
Exit Quick Mask
Click the Standard Mode button in the toolbox to exit Quick Mask and convert the mask to a selection. Alternatively, press the Q key to toggle between standard mode and Quick Mask mode to make sure that the selection is correct for the work you're doing to the image.
Filtering for Graphic Effects
While still in Quick Mask mode, you can use any of Photoshop's filters to apply unique textures to the mask. When you switch to standard mode, the texture of the selection is reflected as you edit the image.
Using the Type Tool for Text Selections
While in Quick Mask mode, you also can use the Type Mask tool to create text selections. Fill the selections with the mask to make the selection active, and then modify the selection further with filters or other tools.