How do I turn off anti-aliasing in Photoshop?

To turn off anti-aliasing in Photoshop, you typically control this setting on a tool-by-tool basis directly within the application's Options bar.

Based on the provided information, specifically regarding selections:

You can turn off anti-aliasing for selection tools by deselecting the "Anti-alias" option in the Options bar whenever you have the proper selection tool activated. After deselecting the option, you must then create the selection again for the change to take effect.

Understanding Anti-Aliasing in Photoshop

Anti-aliasing is a technique used in digital graphics to smooth out jagged edges, particularly on diagonal or curved lines. It does this by blending pixels along the edges with surrounding background pixels, creating a softer transition.

While often desirable for a smooth look, there are times when you might want crisp, hard edges, such as when working on pixel art or specific graphic designs. Turning off anti-aliasing prevents this pixel blending, resulting in sharp, blocky transitions.

Turning Off Anti-Aliasing for Selections

As mentioned in the reference, the primary way to control anti-aliasing for selections is via the Options bar.

Here's how you typically do it:

1. Select a Tool: Choose a selection tool from the Toolbar (e.g., Marquee Tool, Lasso Tool, Magic Wand Tool).
2. Check the Options Bar: Look at the Options bar, which appears usually near the top of the Photoshop window, below the menu bar. This bar changes depending on the active tool.
3. Locate and Deselect "Anti-alias": Find the checkbox labeled "Anti-alias" (or similar). Click on the checkbox to uncheck it.
4. Make Your Selection: Create your selection on the canvas. The edges of this new selection will now be hard and jagged, without anti-aliasing.

Note: Turning off anti-aliasing only affects selections made after you have unchecked the option in the Options bar. Any existing selections will retain their original anti-aliasing setting.

Tools Where You Find the Anti-Aliasing Option

While the reference specifically mentions selections, the anti-aliasing option is commonly found with various tools that create shapes or defined edges. For selection tools, it's a standard feature.

By deselecting the "Anti-alias" option when using these tools, you ensure that the subsequent selections have sharp, pixelated edges instead of blended ones.

Remember to reactivate the "Anti-alias" option when you want smooth edges again for future selections or other operations.