keep in mind the weight of your glass or whatever your using and aswell how you support said weight 6 mm glass is pretty heavy I'm using 4 corners and two straights to hold a 18x30 inch pane with un-vaped/treated parts and still seems solid, this was placed aprox. chest height and is indoors where I may or may not have protected feet so I wanted to be extra sure I wasn't guna lose toes