Troubleshooting2026-02-25/4 min read
Why does my iPhone case become loose after a few months?
Case flexing and loose borders are frustrating. Learn the material causes and how to prevent case stretching.
IP
Rohan Mehta/The iPhone Project Journal
It is highly frustrating when a case that fitted perfectly on day one becomes loose, with saggy edges that slip off easily. This is caused by material stretching in cheap TPU covers.
TPU is an elastic polymer. When you repeatedly remove the case or pull it from the corners, the polymer chains stretch and fail to return to their original shape.
To prevent this: 1. **Limit case removal**: Avoid taking the case off repeatedly. 2. **Choose hybrid cases**: Look for covers featuring a rigid polycarbonate backplate, which holds the TPU borders firmly in place, preventing stretching.