Abstract: The present disclosure is drawn to an ink sets, printed articles, and related methods. The ink set can comprise a pre-treatment ink and a reflective ink. The pre-treatment ink can comprise a first liquid vehicle and inorganic pigment particles having an average particle size ranging from 20 nm to 300 nm and a refractive index of less than 2. The reflective ink can comprise a second liquid vehicle and metal oxide particles having an average particle size from 3 nm to 180 nm, wherein the average particle size of the metal oxide particles is smaller than the average particle size of the inorganic pigment particles. The reflective ink is formulated to have a metallic luster when overprinted on pre-treatment ink.