Filter Forge doesn't seem to save as mtl - and appears to be more oriented to work with PhotoShop than KeyShot - 1000 USD is a lot to upgrade just to get materials editing capabilities - unless its 149 for Substance Design - however, KeyShot Pro 6 has a much more sensible editor (in my opinion) - if you cough up 850 USD for the sensible practicality and user friendly interface controls! Sheeesh!