You need to firstly clean the original screen printing off the disc. Use a solution of caustic sode diluted with water. Once clean 9a day or two) use a heat gun or hair dryer to soften the plastic and get as much of the curl our as you can. Be very careful not to go overboard with the heat. You can also use a moderate oven to heat the plastic up. Once you have as much of the curl out as possible, re-heat the plastic disc and place on a flat surface; place another flat item (a slab of steel, glass or wood) over the disc and then place a heavy object on top of that. Leave for a few hours and you should have a flat disc again. KP
