Examination of Painting on Metal Support by Terahertz Time-Domain Imaging C. L. Koch Dandolo 1 & A. M. Gomez-Sepulveda 1,2 & A. I. Hernandez-Serrano 1 & E. Castro-Camus 1 Received: 26 May 2017 /Accepted: 9 June 2017 # Springer Science+Business Media, LLC 2017 Abstract Two paintings on metal support have been imaged by terahertz time-domain imaging (THz-TDI) in a reflection setup and the X-ray radiographs were also recorded. The study was performed for testing the terahertz radiation (THz) as an imaging method alternative to X-ray radiography, which suffers several limitations in imaging paint layers on metal support. While the information regarding the paint layers of the paintings was almost lost in the records provided by the X-ray radiography, THz-TDI demonstrates the ability to provide important information about them, despite the presence of the underlying metal. Keywords Terahertz time-domain imaging . Painting on metal support . Terahertz . X-radiography . Imaging . Cultural heritage 1 Introduction 1.1 Painting on Metal Support and Examination Technologies The time at which painting on metal support found their largest diffusion in Europe corre- sponds to the middle of the sixteenth century, while the decline of this painting technique started at about the second half of the seventeenth century [1]. Nevertheless, the use of painting on metal continued throughout the eighteenth century and later in Countries such as France, Spain, and, consequentially, in the Nueva España (currently Mexico). A complete overview about the history of the paintings on metal support can be found elsewhere [2]. J Infrared Milli Terahz Waves DOI 10.1007/s10762-017-0409-7 * C. L. Koch Dandolo corinnakd@gmail.com 1 Centro de Investigaciones en Óptica A.C, Loma del Bosque 115, Lomas del Campestre, 37150 León, Guanajuato, Mexico 2 Escuela de Conservación y Restauración de Occidente, Analco No. 285, Barrio de Analco, 44450 Guadalajara, Jalisco, Mexico