Advanced photonic techniques for the analysis of the composite French folding fan Iacopo Osticioli, Daniele Ciofini, Silvia Calusi, Eva Martelli, Marta Mascalchi, Simona Lombardi, Pier Andrea Mandò, Juri Agresti and Salvatore Siano Eur. Phys. J. Plus, 136 11 (2021) 1105 Published online: 02 November 2021 DOI: 10.1140/epjp/s13360-021-02068-6