How do you refine edges in Photoshop?

To refine edges in Photoshop, you primarily use the Select and Mask workspace, which allows for precise edge adjustments.

Here's a breakdown of the process:

1. Make a Selection: Begin by making a rough selection of the object or area you want to refine using any selection tool (e.g., Lasso Tool, Quick Selection Tool, Magic Wand Tool).

2. Open Select and Mask: Go to Select > Select and Mask in the top menu. This opens the Select and Mask workspace.

3. Choose a View Mode: In the Properties panel (usually on the right side of the screen), select a view mode that helps you see the edge clearly (e.g., Overlay, On Black, On White).

4. Use the Refine Edge Brush Tool: In the toolbar on the left, select the Refine Edge Brush Tool (it looks like a brush with hair strands). This is the primary tool for edge refinement.

5. Paint Over the Edges: Carefully paint over the edges of your selection, focusing on areas where the selection isn't clean or where there's hair, fur, or other complex details. The tool intelligently samples the colors in the area and improves the selection.

6. Adjust Global Refinements: In the Properties panel, adjust the following settings to further refine the selection:

   • Smooth: Reduces irregularities in the edge boundary for a smoother outline.
   • Feather: Blurs the edge to create a softer transition between the selection and the background.
   • Contrast: Increases the sharpness of the edge by defining the difference between foreground and background pixels.
   • Shift Edge: Moves the edge inward or outward. A negative value shrinks the selection, while a positive value expands it.
   • Decontaminate Colors: Replaces color fringing along the edges with the color of nearby fully selected pixels. This is particularly useful for removing color halos around hair or fur.

7. Output Settings: Choose your desired output from the "Output To" dropdown menu in the Properties Panel:

   • Selection: Outputs the refined selection to a selection.
   • Layer Mask: Creates a layer mask based on the refined selection, allowing for non-destructive editing. This is generally the preferred method.
   • New Layer: Creates a new layer with the refined selection.
   • New Layer with Layer Mask: Creates a new layer with the refined selection and a layer mask.
   • New Document: Outputs the refined selection to a new document.
   • New Document with Layer Mask: Outputs the refined selection to a new document with a layer mask.

8. Click OK: Click "OK" to apply the changes and exit the Select and Mask workspace. Your refined selection (or layer mask) will be applied to your image.

By using the Refine Edge Brush Tool in conjunction with the Select and Mask workspace's adjustment sliders, you can achieve highly accurate and professional-looking edge refinements in Photoshop.