I do use a piece of float glass on my 3D printer bed, and it works well enough. Maybe I'll see if I can figure out how much it distorts when heated (not enough

I do use a piece of float glass on my 3D printer bed, and it works well enough. Maybe I'll see if I can figure out how much it distorts when heated (not enough to cause a noticeable problem with the relatively low-precision stuff I've been making thus far). Some people do use borosilicate glass (like Pyrex) for this, but I've been satisfied so far with a piece of regular float glass window stock I had cut to size at Lowes.