Just wondering if anyone can clarify something for me, It's about glass thickness so bear with me please! If your are using toughened glass instead of plate glass do you have to use the same thickness or because toughened glass is so much stronger(approx 5 times so I'm told) does it stand that you can use a thinner glass, eg if the calculator tells you that you need 15mm thick glass (I'm presuming thats plate/annealed glass) would 10mm thick toughened glass be acceptable? Thanks