100mm Borosilicate Glass Petri Dish with Lid - Lab-Grade, Sterilizable (Case of 60) - Ideal for Microbiology, Cell Culture & Science Experiments

So, I've bought 120 plates, half in 90mm and half in 100mm. There are imperfections and downright flaws with these plates, but at at fraction of the price of other plates, I can deal with it. I would say one in ten plates has a minor issues, like it is warped, and the lid doesn't sit flush, or there was a little piece of something stuck in the glass. I find it better to use plastic wrap to seal them because the gap would be difficult to cover with parafilm. Out of the 120, maybe five or so had something seriously wrong. Chipped, cracked, super deformed or super thin glass. I know how to handle a plate, and I put my thumb through one of them near the edge and I wasn't even putting a whole lot of pressure on it. If you want every plate to be perfect, don't buy these. If you can deal with some wonk, and want a good deal, go for it.