The next time your paint job leaves leftover paint in the can there are a couple of things you can do before you store it that will make your future paint jobs easier. First of all, mark the outside of the can with a line that gives you the level of the liquid left. This way you will always know how much is inside the can without opening it. Secondly, paint a large swatch of the paint on the can top so you know exactly what color is in the can. You’ll then be able to do touch ups without any wonder or even reuse this paint for another project.