Many people Don’t realize that there are NO standards for paint sheen. What one paint manufacture considers a flat paint may be another manufactures eggshell. The sheen of a paint is often the big obstacle when trying to match a paint color. Paint color matching is now relatively easy. Everyone has seen the paint matching computers at the big box and paint stores and there are phone apps and mini computer gadgets that will match a color on the spot.
Matching a paint sheen is a bit more of a challenge. There isn’t anything that can be added to a paint to increase the sheen so often when matching colors the sheen is a little bit more of an art.
If you know what you already have on your walls, for example, then it is simply a matter of going out and getting more of the same. However if you are not sure what the paint is, matching the sheen will take a trained eye.
The old rule of thumb was to put paint with a higher sheen in kitchens and bathrooms and lower sheen paints in the common areas of a home. This still holds true to an extent however there are now paints with lower sheens that are still cleanable/scrubbable. Often if you look closely at the scrubbable flat paints you will see that they actually have more sheen then a true flat product.
When you buy paint for a project in your home I recommend getting an extra gallon for future touch-up. In large part because of the sheen issue and while a paint manufacture may have been in business for a long time, certain paint lines are discontinued from time to time. When The Painting Company is doing a project for you we always provide extra paint for future use.
Always store paint out of temperature fluctuations. Not in the garage. Most paint cans today are not metal so rusting of the can is not an issue. If you are not storing a full can of paint, transfer it to a smaller container (label it well) to reduce airspace to a minimum.