Assessment of methods for determining the colour properties of denim fabric engraved with laser

Abstract In this study the decolorization of denim exposed to a 1064 nm laser light was investigated. The bleaching procedure proceeds by irradiating the fabric by directing the beam with a scanning head. The effect of bleaching is obtained by processing parallel lines, hatches, on the fabric with different beam power and distance between the lines. Treatment of indigo dyed 100% cotton denim fabric was made by Ytterbium pulsed fiber laser with 20W output power at 1064 nm wavelength and frequency of 20 kHz. Colour fading was investigated using a Spectrophotometer and evaluation of Weber contrast. The L*, a*, b* coefficients are compared to digitally measured Weber values. Based on this, the research reveals a set of laser processing parameters to produce faded denim effects with different colour impact appropriately for modern design industry.