Light of wavelength 632.8 nm scattered from a single natural fibre onto an observation plane perpendicular to the fibre axis was observed to form rings which converge to a point defined by the incident beam. Using a series cone model for natural fibres, these rings are shown to be due to reflection from a curved surface inclined at some angle to the fibre axis, such as scales found on the fibre surface. Measurements of relative intensity and position associated with prominent rings in this observation plane were made. These measurements were used to determine all possible scale angles illuminated by the incident laser beam. Results show that although some 300 scales were illuminated only a few intensity peaks corresponding to prominent rings were detected. Therefore, suggesting that a few prominent scales occur repeatedly within the illuminated section on the fibre. Results also show that both positive and negative scale angles exist along a single fibre. Ranges of scale angles obtained for coarse, fine and super fine wool, mohair and cashmere fibres were found to be: 0.2degrees to 8.6degrees +/- 0.05degrees, 0.5degrees to 7.6degrees +/- 0.05degrees, 2.2degrees to 3.0degrees +/- 0.05degrees, 0.1degrees to 3.6degrees +/- 0.05degrees, 0.1degrees to 2.6degrees +/- 0.05degrees and respectively. (C) 2003 Kluwer Academic Publishers.