Compositions and methods for rendering a substrate more grease-resistant are disclosed. Treatments, such as aqueous-based treatments and/or emulsions, can be applied to the surface of a substrate, such as paper-based materials, which can be dried to form a treatment layer imparting grease resistant properties. In some instances, the treatment includes an acrylic-based polymer, which can impart grease-resistance, and one or more complementary components (e.g., a polymer and/or oligomer) that can make a layer less brittle (e.g., lowering the T.sub.g of the layer relative to a layer of acrylic-based polymer). Such treatment layers can retain their grease resistance even when creased, allowing the use of such layers in applications such as food processing. Other additives, compositions, and methods are further developed.