What's the best way to mix, work and store KRST? Does one prepare and keep it as a working solution from the liquid (say, mix up a litre) or use it one shot? How long can it keep in the tray? How toxic is it just sitting in the tray evaporating? Some explanation about when to use what ratio would probably help me too. I'm toner Agfa RC paper with it. Thx. Oh yeah, latex gloves are OK or do I need rubber gloves?