From their website:
"The Mattress Factory celebrates its 35th Anniversary with a special community party. Bring the family, design your own party crowns, make scribble machines, go on a gallery scavenger hunt, share your favorite Mattress Factory memories and eat some anniversary cake!
Admission to museum and community party are pay what you wish"
Check out http://www.mattress.org/index.cfm?event=Events&d=2/23/2013 for more information