Select the crop tool (), or press C to switch from the current tool to the crop tool.

Move the pointer into the image window, and drag diagonally from the upper left corner to the lower right corner of the completed artwork to create a crop marquee.

After you finish dragging in Photoshop, look on the tool options bar and make sure that the Perspective check box is not selected.

Adjust the crop marquee, as necessary:

• If you need to reposition the crop marquee, position the pointer anywhere inside the marquee and drag.
  
  
• If you want to resize the marquee, drag a handle.
  
  

When the marquee is positioned where you want it, press Enter (Windows) or Return (Mac OS) to crop the image.

The cropped image may include some scraps of the gray background from which you selected and removed shapes. You’ll fix that next.

Drag a selection marquee around an area that has some of the unwanted gray background, being careful not to include any of the art work that you want to keep inside the selection.

In the toolbox, select the eraser tool (), and then make sure that the foreground and background colors are set to the defaults: black in the foreground and white in the background.

Drag the eraser over the gray in the selection area.

Notice that if you accidentally go outside the selection, nothing is erased. Only pixels within the selection are replaced with white as you erase; the rest of the image is protected. Next, you’ll use a different technique to remove unwanted pixels.

Select another area with only unwanted pixels, and then press Delete.

Continue selecting and erasing or deleting until you finish removing all the unwanted scraps of background.

Choose File > Save.

The collage is complete.