Despite the rapidly growing interest in laser-induced graphenization, underlying mechanisms remain poorly understood . The pyrolysis of polyimide involves the transformation of a homogeneous polymer solid into a foam-like structure due to the rapid generation of gaseous products during the photothermal process . The pyrolysis of cellulose is more challenging, since the porous and fragile nature of the substrate, combined with its high oxygen content and lack of aromaticity, reduces the window of process conditions suitable for successful graphenization. Two key parameters help in this regard: pre-treatment with a fire-retardant solution and laser defocusing . The former prevents complete combustion of the cellulose fibers by promoting recombination reactions, and the later effectively exposes the substrate to multiple laser pulses. To explore this idea, we screened a number of inorganic fire-retardant salts together with different laser parameters. We identified ammonium sulfamate as the best pre-treatment agent, yielding a sheet resistance as low as 23±2 Ω sq -1 (Figs. and). It should be noted that this value is significantly lower than previously reported sheet resistances and comparable to laser-pyrolyzed polyimide (down to 15 Ω sq -1 , Table ) Next, taking inspiration from furnace-based pyrolysis , we employed Raman spectroscopy and wide-angle X-ray scattering (WAXS) to investigate the formation of graphenized cellulose (Fig. ). We examined laser powers between 1.2 and 4.8 W at 10 mm laser defocus and a speed of 16 cm s -1 . The lower bound approximately corresponds to the power that results in a degree of visible carbonization, and the upper bound corresponds to the maximum power the paper can endure without compromising mechanical integrity (Fig. and). At low powers, we observed superficial carbonization of cellulose fibers with no detectable conductivity (Fig. ), while increasing the power beyond 2.4 W led to a sudden drop in sheet resistance.