Try answering the question that was asked.
Both face and chest decals are 256x256 in dimension, and are found in base/data/shapes/player/faces and base/data/shapes/player/decals, respectively.
However, they require a minimized preview image, 64x64 pixels in size, to be placed in base/client/ui/avatarIcons/face and base/client/ui/avatarIcons/decal.