Thea Render uses a unique physically-based material system that delivers highest quality realism to your images. There are four reflectance models (Basic, Glossy, SSS and Thin Film) and one special used as coating for layered materials. Thea Render materials are physically-based meaning that the models used, not only do not violate any physical laws, but they have been also developed based on an analytical physical framework. All materials have a uniform logic, and can be used as building blocks for even more complex materials through an innovative layering scheme. The materials may not only be mixed together (horizontal direction), but also be stacked or modulated by special coating material (vertical direction). The modulation results in highly energy conserving materials which simulate real world materials – usually involving paints and varnishes – and are in general too difficult to produce from single material models.

Various phenomena are also supported like thin film interference (for example, a color rainbow seen on bubbles and CDs), coating absorption (for example, an oily layer on a metallic surface) while volumetric scattering (and its special case of sub surface scattering) is also supported by the unbiased engines.