mostly involving a multitude of elaborate and laborious processing steps, from high energy irradiation to chemical treatment, including plasma treatment, [14][15][16][17][18] gamma irradiation, [19] electron beam irradiation, [20][21][22] ion irradiation, [23,24] and chemical treatment [25,26] have been thoroughly investigated. Near infra-red lasers have been used extensively to write and mark on PE blended with additives, fillers, pigments, or dyes which enhance the absorption of the laser energy. Three main surface reactions are employed to mark the surface. [27] The first one consists of increasing the local temperature high enough to cause thermal degradation of the polymer. The charring of the polymer forms a dark marking contrast. The second surface reaction consists of using foaming agents. During the degradation of this additive, gas is released resulting in the foaming of the polymer. The third writing method is heating and/or degrading one colorant in a colorant mixture blended in the polymer, resulting in the presence of only one colorant in the irradiated regions, thus a change of color. [28] Most of these methods produce black marking/writing, require a tight control of the laser operating parameters, and also depend on mixed colorant systems stability. Other patterning techniques such as inkjet printing are not suitable because of the poor adhesion properties of PE or require preliminary treatment such as Corona treatment. Therefore, it is still challenging to write/mark non-colored patterns on PE using simple and reliable methods. Moreover, the abovedescribed methods are predominantly performed with close to isotropic polyolefines and very little literature exists on the patterning of drawn HDPE. This paper reports a new marking route to produce optical patterns on drawn HDPE by direct laser writing with a pulsed UV laser.Optical images were written on solid state drawn blends of high density polyethylene (HDPE) with UV absorber 2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol (BZT) at 2 and 5 wt% loading, called respectively PE-2 wt% and PE-5 wt%. The drawn HDPE films are irradiated by direct laser writing with a pulsed UV laser (355 nm, 10 Hz, 2 ns) at various laser doses. Lines are written on the drawn HDPE films by the overlapping of the laser pulses when moving the sample at a constant speed during irradiation. In Figure 1, a schematic representation of the writing process, a photograph and polarized optical microscopy (POM) images of line patterns at Laser Writing Optical patterns are produced on the surface of drawn linear polyethylene containing 2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol (BZT), a photothermal dye, by direct laser writing. The photothermal dye absorbs the UV light and dissipates heat in the polyethylene film. This heat locally results in the melting, shrinking, and recrystallization of PE and the loss of the fibrillar crystalline morphology which is typical for these materials. By using this writing method, an optical image can be obtained by controlling the local UV irr...