Lincoln matte proof cents are very scarce as a group, and the 1915 proof cents are especially challenging. Relatively few were made, especially in comparison to the higher-mintage pieces of the era, such as the 1909, 1910, or 1913 matte proof cents. Distinguishing the 1915 proof cent from its business-strike counterparts requires a sharp eye and a decent loupe. Matte proofs feature squared-off rims, fine details, and granular fields.