Keep your extra paint fresh for a looooooooooooong time!
There's nothing more annoying than to save old paint cans for years... just in case you need to make a little touchup... to find the paint as dry as the Sahara! There are a few things you can do to preserve and protect your paints
Repackage your paints if you want them to last...
If you have less than a quart of paint left in a gallon can, don't continue to store it in the gallon can. If you do, next year for touchups when little Freddy puts his brother's head through the wall, you will be out of luck!
Why does paint dry in the can? Air in the can will cause oil and latex paints to thicken or crust over. With latex paints, the can may even rust!
One easy solution is to transfer the paint to a quart paint can, available at most paint stores. A quart is plenty for most touchups (a quart will cover up to 10' x 10'). Label it with the paint name and number, manufacturer's name, and the date.
P.S. Noting the room the paint was used in will be helpful years from now when you can't even remember your wedding anniversary date. Not a good example? Arrgh!
Special Tip for Oil Paints...
Adding a small amount of linseed oil or Penetrol (an oil paint additive from the Flood Company) to the paint WITHOUT MIXING IT will provide a protective layer that will slow down drying for quite a while!
Unfortunately, this will not work for latex paints. Repackaging is the best way to preserve them!