The Clone stamp tool can be used to paint information from one document to another in both Photoshop and Elements. With more than one document open, you can Alt click (Mac: Opt click) the source document or source layer and then click on the new document to “paint.”
The full version of Photoshop has a really handy panel that allows you to define up to five source documents at one time and switch between the sources with one click. Choose Window > Clone Source to open the Clone Source panel.
In the panel, you’ll see a row of 5 clone stamps across the top. To define a source, click one of the icons. Alt click (Mac: Opt click) the document or layer you want to use as the source. Now choose the second icon and Alt click (Mac: Opt click) the document or layer you want to use as the second source. Repeat to set as many sources as you’d like.
Now select the title bar of the document you are painting to select it. Click one of the clone source icons you have defined and click on your document to paint. To switch sources, just click a different icon.