I thought this was really interesting and you might be interested to. For some time I have made picture frames with two dovetailed wooden splines about a saw kerf thick by ½” wide to hold the corners together rather than a nail and glue alone.
A litre, for metric members, is equal to 1 kilogram so here we have 5 kilos, which is a fraction over 11 pounds, hanging from a splined joint made from a moulded section of pine ¾” x ¾”.
I thought others might rise to the challenge and demonstrate a method using wood and glue alone that matched or surpassed this in strength.
-- Paul Sellers, UK http://paulsellers.com/paul-sellers-blog