Terraskin is about 3/4 mineral powder to 1/4 non-toxic resin combined to make a paper similar to Yupo which is 100% polypropylene. I  have used inks, watercolours, thinned acrylics and coloured pencils on both.  The Terraskin is slightly more textured than the very slippery Yupo but I enjoy using both.  Watercolour sits on top and takes days to dry in puddles which can be effective. Absorbing the paint with a paper towel leaves interesting shapes as well.  There are many excellent images and comparisons online.