Adding depth to a picture frame to make a shadow box is a craft project that anyone can do. Shadow boxes allow you to display three-dimensional memorabilia and artifacts that will not fit into a flat picture frame. All of the materials necessary to transform a regular picture frame into a shadow box are at your local home improvement store.
Measure the overall width and the height of the picture frame you wish to make into a shadow box, along with the width of the trim on the frame. The 2 to 3 inch wide wood trim listed as part of the necessary items will determine the depth of your shadow box. Shadow boxes range from 1 1/2 inches wide to 3 inches wide, but this one is custom, so make it as wide as you like. You will need two pieces of trim equal to the overall width of the frame and two pieces equal to the overall height of the frame. Your back board should be the same dimensions as the overall width and height of the picture frame. If you do not own a saw, have the clerk cut the trim and the back board to size for you. They may also route a groove in the trim to hold the back board in place.
Cut the trim to size and route grooves along the back of each piece for the back board. Sand the four wood trim pieces, then clean off any sanding debris. Stain the trim completely on both sides and both edges. Let the stain dry and apply a second coat.
Remove the existing back from the picture frame. This piece may be used in lieu of new back board if the size is accurate. Most shadow boxes hang on the wall, so if you are using the existing back of the picture frame, you may need to remove the stand that is attached. If you are using new material, apply spray adhesive to the back board and cover it with a piece of felt, sized to fit.
Tape the perimeter of the glass on the back side of the frame, which will be the inside of the shadow box. This will prevent any glue that may run down the side from sticking to the glass. Lay the frame face down and run a line of glue along the top edge of the frame trim. Press the new wood trim flush against the frame, making sure that the routed edge is not adjacent to the glass. Add finishing nails to hold the trim in place. Repeat this process for both sides of your shadow box. Remove the tape after the glue dries.
Attach the items you wish to display onto the felt of the back board with pins or Velcro. Slide the backboard into routed grooves on the trim sides. Set the bottom trim piece in place and attach it to the shadow box frame with wood screws. This will allow you to remove it easily if you should decide to change your display.