17. Next, we're going to add a gradient to the Background layer. This will create a "White Limbo" effect. This effect is useful so that you don't have to create a surface for the box to be resting on. To create this effect, select the Gradient tool.
18. Be sure that the gradient goes from a gray to white.
19. Select the Background layer.
20. Use your Gradient tool to draw straight down from the very top of the canvas down to the bottom. When you are done, the background should look similar to the image below:
21. Now it's time to add some shadow behind the box.
22. Create a new layer titled "Shadow". Make sure this layer is ordered below the "Box" layer.
23. Select the Polygonal Tool and draw the selection area for the shadow of the box (on the "Shadow" layer). See image below:
24. Now using the Paint Bucket tool, fill in the selection area for the shadow with a dark gray color.
25. Select Filter > Blur > Gausian Blur.
26. Adjust the slider at the bottom of the Gausian Blur window until the blur of the shadow looks realistic.
27. Click OK to close the Gausian Blur window. Your image should look similar to the one below:
