How to Selectively Erase in Photoshop CS6
The eraser tools in Photoshop CS6 let you erase portions of an image to the background color, to transparency, or even to the way your image looked earlier in your editing session. There are three eraser tools — the regular Eraser, the Magic Eraser, and the Background Eraser. All three share a tool flyout menu.
The eraser tools look like real erasers, so you can’t miss them. But just in case you do, press E and then Shift+E to toggle through the three tools.
When you erase pixels, those pixels are gone. Gone. For good. Before using the eraser tools, it might be wise to make a backup of your image. You can save the image either as a separate file or as another layer. That way, if things run amok, you have some insurance.
The Eraser tool allows you to erase areas on your image to either the background color or to transparency. Select the Eraser tool, drag through the desired area on your image, and you’re done.
If the image contains just a background, you erase to the background color. If the image is on a layer, you erase to transparency.
This tool is in the same category as the Lasso tool. It’s quick; it’s easy, but it has limited applications. Use it only for minor touchups. The Eraser tool definitely isn’t a tool to use on its own for making accurate selections.
The most useful function for the Eraser tool is to clean up channel masks. Set the mode to Block, zoom into your mask, and clean up those black and white pixels.
These options on the Options bar control the Eraser tool:
Mode: Select from Brush, Pencil, and Block. When you select Brush or Pencil, you have access to the Brush Preset picker panel to the far left of the Mode option.
Use the Brush Preset drop-down picker panel to select from a variety of brush sizes and styles. Block has only one size, a square of 16 x 16 pixels. But because the block size remains constant, if you zoom way in, you can perform some detailed erasing.
Opacity: Specify a percentage of transparency for the erasure. Opacity settings less than 100 percent only partially erase the pixels. The lower the Opacity setting, the less it erases. This option isn’t available for the Block mode.
Always use Pressure for Opacity, Always use Pressure for Size: If you have a pressure-sensitive drawing tablet, you can select these two options. If not, the Brush Preset controls the opacity and size.
Flow: Set a flow rate percentage when using Brush mode. Flow specifies how fast Photoshop applies the erasure and is especially handy when using the Airbrush option.
Airbrush: Click the button when using Brush mode to turn your brush into an airbrush. With this option, the longer you hold your mouse button down, the more it erases.
Erase to History: This option allows you to erase back to a selected source state or snapshot in the History panel. You can also hold down Alt (Option on the Mac) to temporarily access the Erase to History option.
Brush Panel: Click the toggle button to bring up the full Brushes panel.