The Background Eraser Tool clears content of background layer to transparency:
- In the Toolbox, select the Background Eraser
Tool. - Choose brush size and style*.
- Choose in Layers palette Background.
- Erase.
- The gadget Sampling on the Options bar
allows to select one of three erasing modes:
- Continuous (default method) allows to erase everything.
- Once allows to erase only color you first click; for example if you start a stoke on a red area the tool erases only red pixels.
- Background Swatch allows to erase only pixels containing current background color.
- Tolerance gadget sets the tool's sensitivity.
- Limits defines range of the tool: all over image (Discontiguous), only adjacent areas (Contiguous) or only inside pixels (Find Edges).
- Protect Foreground Color option disallows to clear pixels containing current foreground color.
* More about choosing brush.

10 Random Photoshop Basics :
10 Random TutorialKit Materials:







More Photoshop: