Something I realised on the issue of micro-plates is that my pair of spring collars weighs 0.5Kg and my screw-on collars weigh 1Kg for the pair. Between them, I can squeeze some 1 lb increments between having to add another pair of 1.25Kg plates. They're a cheap alternative to sourcing and buying micro-plates, especially since spring collars just litter the floor at some gyms.