Heat and pressure will fix that crease.

Yes, you can flatten it. The key is moisture plus weight, applied evenly over time.

Cloth mousepads are basically fabric with a rubber backing. The crease is a set-in memory in the fabric fibers and the rubber. Steam relaxes the fibers, and weight forces them flat while cooling. Skip the dishwasher or soaking — that often ruins the rubber.

Best method: Dampen a thin towel (not dripping), lay it over the crease, and iron on low-medium heat (no steam setting, just dry). Press for 5-10 seconds, lift, repeat. Then immediately put heavy books or a cutting board on the mousepad until it cools. If the crease is stubborn, re-dampen and press again. For rubber-backed pads, keep the iron moving and don’t leave it in one spot — you can melt the backing.

If you don’t have an iron, try rolling the pad backward (opposite the crease) overnight, then stack heavy books on it for a day. Works about 50% of the time. The iron method is more reliable.

You will probably get it 90% flat — close enough that you won’t notice while gaming or working.