Interesting that other methods were mentioned, but that is our way.
Edge bending is best done two ways.
One way involves a $12,000. machine and $1000 in special dies.
The other way is hammering the outside edge.
As Frosty mentioned, 1/4 is way easier, I wouldn't bother using 1/8", too much effort.
Whenever I have to make curved hinges I always hammer the edge. Twisting, curling and warping are dealt with, corrected on the anvil while hammering in the curve; once you get practice at it, it should come off the anvil flat.
It is remarkably easy to correct and do an accurate job.