Can You Store Spray Paint on Its Side?

Spray paint cans are generally designed and intended for upright storage — storing them on their side for extended periods isn't catastrophic, but it introduces real, avoidable risks that upright storage simply doesn't have.

1. Why upright storage is the standard recommendation

A spray can's internal dip tube (the small tube that draws paint up to the nozzle when the can is used) is designed to reach the paint at the bottom of an upright can — stored on its side for a long period, paint and propellant can settle and separate in a way that affects how well the can sprays when it's eventually picked up and used.

2. What can happen with extended on-side storage

• Uneven pigment settling — pigment can settle unevenly along the side of the can rather than the bottom, potentially causing inconsistent color or clogging when the can is finally shaken and used.
• Dip tube positioning issues — in some cans, sustained sideways storage can affect how reliably the dip tube draws paint once the can is returned to an upright position.
• Valve or seal concerns — prolonged sideways storage, particularly in a can that isn't perfectly sealed, carries a slightly higher risk of minor leakage around the valve compared to upright storage.

3. Brief, occasional sideways storage — not a major concern

A can lying on its side briefly (during transport, for instance) isn't the same risk as months of sustained sideways storage — the concern scales with duration, and a can that's spent most of its life stored upright, with only occasional brief exceptions, is unlikely to show meaningful problems from that limited exposure.

4. What to do if a can has been stored on its side for a long time

1. Return the can to an upright position
2. Let it sit upright for a period (some recommend at least a day) before use,
   allowing contents to resettle
3. Shake thoroughly per the label's instructions before spraying
4. Test spray on scrap material first to check for even color and spray
   pattern before using on the actual project

5. Standard storage recommendations, beyond just orientation

Storing spray paint upright, at a moderate temperature (avoiding extreme heat or cold, and definitely avoiding freezing, following the same temperature sensitivity covered for other paint types), and away from direct sunlight, gives the best chance of a can performing reliably whenever it's eventually used.

6. The practical takeaway

Upright storage is the safer default and worth following as standard practice — a can that's occasionally been on its side briefly isn't ruined, but genuinely long-term sideways storage introduces real, avoidable risks to how well that can will spray when it's finally needed.