Polymer clay can be stored for a very long time, even several years. Because it does not contain any water, you don’t have to store it in special air tight containers. However there are some rules or recommendations which will help you to keep your clay in good condition for a longer time.
Keep it wrapped
If you keep the clay wrapped in the original package, or in a zip lock bag, it will be protected from dust and dirt.
Keep colors separate
If two color blocks of polymer clay would be sitting next to each other for some time, they would eventually start to blend into each other. For this reason it is better to have each color in a separate bag.
Keep it in the dark
Excessive exposure to sunlight or heat may slowly destroy the clay as well. I keep it in a non transparent box and I pay attention that the box with polymer clay is not in direct sunlight. There are existing very practical transparent boxes and many other people are using them. They are also fine to use, if they are stored in a dark place afterwards.
How long can the finished pieces wait for the baking?
There is no limit to this. For some energy efficiency is good to wait with baking until there are several pieces ready to be baked. (Just make sure they are protected from dust and that they are not touching each other)