Can someone show me how this is done?

pǝlloɹ┴

Could someone show me how the boarder of this image is done? I've tried a few times but havn't been able to get it right

.Wiki

Looks like a simple brush with a lot of noise and irregularities.

Obscura

These at the brush settings gave me really close result:
Shape dynamics: size jitter, angle jitter, roundness jitter
Scattering
Dual brush could help too.

pǝlloɹ┴

Thanks for the great tips! I will mess around with it and see what happens. Would a smudge tool be used in this?

.Wiki

Yeah the smudge tool would be great for those washed out corners. There is no unique way to achieve this result .