A material comprising a transparent substrate coated on one face with a stack of thin layers successively comprising, starting from said face, an alternation: - of three silver-based functional metal layers denoted, starting from the substrate, first functional layer Ag1, second functional layer Ag2 and third functional layer Ag3, with physical thicknesses respectively Ta1, Ta2 and Ta3, and - of four dielectric coatings denoted, starting from said face of the substrate, M1, M2, M3 and M4, with optical thicknesses respectively To1, To2, To3 and To4, each dielectric coating comprising a dielectric layer or a dielectric assembly of layers, so that each functional metal layer is positioned between two dielectric coatings, said material being characterized in that: - the physical thickness Ta2 of the second functional layer Ag2 is greater than the physical thickness Ta1 of the first functional layer Ag1, with 1.40 ≤ Ta2/Ta1 ≤ 1.60; - the physical thickness Ta3 of the third functional layer Ag3 is greater than the physical thickness Ta2 of the second functional layer Ag2, with 1.05 ≤ Ta3/Ta2 ≤ 1.2; - the dielectric coating M4 exhibits a lower optical thickness To4 than each of the optical thicknesses To1, To2 and To3 of the other dielectric coatings M1, M2 and M3; and - the dielectric coating M3 exhibits a greater optical thickness To3 than each of the optical thicknesses To1, To2 and To4 of the other dielectric coatings M1, M2 and M4. - of three silver-based functional metal layers denoted, starting from the substrate, first functional layer Ag1, second functional layer Ag2 and third functional layer Ag3, with physical thicknesses respectively Ta1, Ta2 and Ta3, and - of four dielectric coatings denoted, starting from said face of the substrate, M1, M2, M3 and M4, with optical thicknesses respectively To1, To2, To3 and To4, each dielectric coating comprising a dielectric layer or a dielectric assembly of layers, so that each functional metal layer is positioned between two dielectric coatings, said material being characterized in that: - the physical thickness Ta2 of the second functional layer Ag2 is greater than the physical thickness Ta1 of the first functional layer Ag1, with 1.40 ≤ Ta2/Ta1 ≤ 1.60; - the physical thickness Ta3 of the third functional layer Ag3 is greater than the physical thickness Ta2 of the second functional layer Ag2, with 1.05 ≤ Ta3/Ta2 ≤ 1.2; - the dielectric coating M4 exhibits a lower optical thickness To4 than each of the optical thicknesses To1, To2 and To3 of the other dielectric coatings M1, M2 and M3; and - the dielectric coating M3 exhibits a greater optical thickness To3 than each of the optical thicknesses To1, To2 and To4 of the other dielectric coatings M1, M2 and M4. - the physical thickness Ta2 of the second functional layer Ag2 is greater than the physical thickness Ta1 of the first functional layer Ag1, with 1.40 ≤ Ta2/Ta1 ≤ 1.60; - the physical thickness Ta3 of the third functional layer Ag3 is greater than the physical thickness Ta2 of the second functional layer Ag2, with 1.05 ≤ Ta3/Ta2 ≤ 1.2; - the dielectric coating M4 exhibits a lower optical thickness To4 than each of the optical thicknesses To1, To2 and To3 of the other dielectric coatings M1, M2 and M3; and - the dielectric coating M3 exhibits a greater optical thickness To3 than each of the optical thicknesses To1, To2 and To4 of the other dielectric coatings M1, M2 and M4.