C cell and C endo : the Celluclast® treatment C cell took place in 4 x 250 mL double-walled glass reactors set up in series, each of them positioned on magnetic stirrers. The reactors were connected to a closed water loop system with set temperature 2 g of o.d. pulp were introduced in a 100 mL glass bottle with thread cap. 50 mL of pH 5.3 citrate-phosphate buffer as well as DEI water to reach 5% PC were added. Temperature was set so the temperature of the pulp suspension within the threaded bottles reached 40 °C. After 15 min the enzymes were introduced and the stirring set on 200 rpm for a 24 h reaction time. This system allowed for 4 simultaneous enzymatic hydrolyses with constant stirring and temperature. After 24 h, the glass bottle was taken off the reactor and enzymes deactivated (10 min boiling water treatment followed by 1 h in iced bath). For the C endo treatment the same procedure was employed but using an acetate buffer (pH 4. Z: high consistency ozonation consisted of pulp pH adjustment to 2.5 with 4N H 2 SO 4 solution at 1-2 % Pulp Consistency (PC), followed by the pulp filtration on no. 2 crucible and centrifugation of the pulp to obtain 38-42 % PC. The pulp was fluffed and put in a spherical glass reactor for ozonation. The ozone generator settings were: input oxygen pressure = 2 bars; current = 0.7 A; ozone concentration ≈ 65 mg/L. The real ozone concentration in the gas flow was titrated from a potassium iodide trap solution by adding sodium thiosulfate. Ozone consumption was calculated the same way by titrating the excess ozone in the reactor's exhaust gas. At the end of the experiment, if the Z stage was followed by a E, Eo, or P stage, the pulp was directly stabilised to the desired (alkaline) pH value and PC by adding DEI water and a 40 g/L NaOH stock solution. TCF fully-bleached pulp was produced in the lab by bleaching Ko pulp with TCF sequence A-Z(0.2)Eo-Z(0.2)Eo-Z(0.1)P.