turn off use compressed files under general options.

create a material collection in the materials library. this will give you an mc6 file and a thumbnail png. 

copy the mc6 file and thumbnail to your pose library, using a meaningful folder name for your product.

rename the mc6 file to a pz2 file extension.

edit the new pz2 file with wordpad (for windows)

change the line that read mtlcollection , and change it to figute.

 

thats it , you now have a working mat pose file.

 

This is the start of an mc6 file

{

version
    {
    number 6
    }
mtlCollection <<<<<<<<< change this
    {
    material 2_SkinHead
        {
        KdColor 0.843137 0.980392 0.980392 1
        KaColor 0.0784314 0 0 1

and this is a mat pose file

{
version
    {
    number 4.01
    }
figure  <<<<<<<<<< to this
    {
    
        {
        KdColor 0.976471 0.976471 0.976471 1
        KaColor 0 0 0 0
        KsColor 0 0 0 1