The invention aims at a laser-markable insulating material and a cable or wire assembly which contains the insulating material. In some embodiments, the laser-markable insulating material can comprisea fluorine-containing polymer and a laser-markable inorganic pigment. The pigment can have an average grain granularity in a range of about 0.4-2 micrometers and/or a middle granularity (d50) in a range of about 0.45-2 micrometers. The insulating material can represent an improved contrast ratio between an initial state and a thermal-aged state without capability reduction of the cable or the wire which comprises the insulating material for satisfying a requirement for industrial standards of arc tracking and propagation.