Step 3: Building the frame.
The frame was 28 7/16 by 2 1/2 inches for the sides and 59 1/8 by 2 1/2 inches for the top and bottom. The TOP extended past the glass and the sides attached to the top and bottom.
I made the slot continuous through all pieces and then glued in some wood into the slot where the glass wasn't and the top met the sides. This was to add strength to the butt joint.
Test fit the wood to the glass to make sure your frame will come together and that the glass does not move. You can make the grooves deeper or add larger pieces of rubber washers to make the fit work. Of course, mine came out perfectly the first time (lucky for me!).
Make sure to sand the wood before putting the frame together. I put a bevel on the glass side to make writing easier. I also stained and finished the wood before assembly
Again, your choice and your lessons in staining or painting are necessary. I used Minwax conditioner and a Early American oil stain with a Minwax clear satin water based acrylic finish.
I used a pocket hole joiner to finish the frame. I guess other ways would be to buy loong screws and screw the frame together or possibly just put a piece of wood over the joint and screw it together.