An object can be formed in an additive manufacturing process, such as FDM, by providing a substrate having at least a surface that is made of a first material, and forming one or more layers of a second material on the surface of the substrate. A Hildebrand solubility parameter of the second material is within about 5% of a Hildebrand solubility parameter of the first material. In this manner, the object part formed by the one or more layers of the second material may be incorporated into the object. In an example, the object includes a first portion and a second portion, the first portion comprises the one or more layers of the second material, the second portion comprises the substrate, the first portion has a first haze value, and the second portion has a second haze value, wherein a percent difference between the first haze value and the second haze value is equal to or greater than about 165%.