Paint products can become contaminated with bacteria or mold, which can lead to a strong, offensive and in some cases, sickening odor. Paints such as poster paints and temperas that are intended for classroom use, and for children, often contain an organic binder that is subject to degradation if not stored properly, or used within a reasonable period of time.
To guard against bacteria and mold, manufacturers of paint products add preservatives to these products. Diluting the product will decrease the effectiveness of preservatives. Below are some tips on storing paint products to maximize their shelf life:
- Store the product in its original container in a cool, dry place and prevent freezing.
- Date and rotate inventory, always using the oldest stock first.
- Thoroughly shake the product before using.
- Remove only enough paint for immediate use. Never return unused portions to the original container.
- Never dilute the product. The addition of water dilutes the preservative's strength as well as the paint. If diluting paint to simulate watercolor techniques, prepare only enough for immediate use.
- Avoid working directly from the original product container. Do not place brushes, hands, or other objects in the container.
- After each use, make sure the cap is returned tightly and that the product is sealed before storing.