Quote from sp614x
This is a 4x HD cape, corresponding to a 64x texture pack.
I am planning to add a bunch of capes including some 2x and 4x HD capes. It will be possible to select one of the capes when donating.. The HD capes will also be available for old donators (of course).
I am currently considering what is the best way to enable custom HD capes. Later this may also be extended to include custom HD skins.
Surely it would be better for the mod to choose the cape based on the resolution of the texture pack?
Who would want a 256x cape with a 16x texture pack? It'd just look dumb.