Sampling from layers
The default behavior of the Magic Wand, Smudge, Blur, Sharpen, Paint Bucket, Clone Stamp, and Healing Brush tools is to sample color only from pixels on the active layer. This means you can smudge or sample in a single layer even when other layers are visible, and you can sample from one layer and paint in another one.
Alternately, you can choose to paint using sampled data from all visible layers. For example, you can use the Clone Stamp tool to clone an area containing pixels from all the visible layers.
To sample from all visible layers:
- Select the Magic Wand tool
, the Smudge tool 
, the Blur tool 
, the Sharpen tool 
, the Paint Bucket tool 
, the Clone Stamp tool 
, or the Healing Brush tool 
. - In the options bar, select Use All Layers.
Note: When you are using tools that sample image data, painting or editing in a new layer where there are no pixels produces the best results when Use All Layers is selected.