I recently melted my hot end loose inside my fan duct rostock hot end capture unit (after a fan settings accident)http://www.thingiverse.com/thing:381808 and thought others might want to use this bed test web for their own bed level testing. Scale it to fit your usable print area and you can tweak the adjustment screw after each pass to get that perfect slightly squished look all over for the first layer. If you have a delta printer you may want to use this one instead: http://www.thingiverse.com/thing:980003