SBT.. i woke up this morning to a test-render that looked like a big pile of poo.  So I took a stab; loaded one of hongyu's stock mats onto the bikini top; then switched it to my trans map and my diffuse map and it rendered beautifully.  Except in SLG and that seems to hate my trans maps period.  Yes, I do use absolute black for fully transparent and absolute white for fully opaque and then tweak stuff in between