king....-.-
Stop trying to make good sigs while you just stick to that height. Are you making sigs for the SOLE purpose of using them in TW, or have you gotten to the bit where you actually like GFX and want to actually do something other than crappy 80px sigs those troubled german teens that run TW make you do?
If it's the latter, I would personally start doing 400x150/400x200 as a staple size....
-.- You simply cannot make a variety of renders fit with such an aspect ratio. Maybe those long renders like a train or a vehicle................but not the usuals.