Skin > Edit Smooth Skin > Export Skin Weight Maps >
Sets the width and height of the image. If the skin has 1000s of CVs or vertices, a large map will ensure the destination skin matches the original skin. However, large maps take more time to save to disk and also use more disk space. A map that is too small might cause inadvertent averaging of the alpha or luminance values.
The default values 512 by 512 work well for most skins. If the skin lots of CVs or vertices, use Map Size values of 1024 by 1024.
If the skin has relatively few CVs or vertices, use values 256 by 256.
If you use a skin made from dozens of NURBS patches, consider using 256 by 256 to avoid wasting lots of disk space.