All this makes it difficult to research techniques of conservation and restoration. Researcher at the University of the Basque Country (UPV/EHU), Ms Enara Artetxe Sánchez has made a study of coloured or illuminated photographs for her PhD thesis. Her work is entitled, Argazki koloreztatuak zaharberritzeko paperean erabiltzen diren zenbait kontserbazio-zaharberritze tratamenduren egokitasunaren azterketa (Research on the suitability of certain of the on-paper conservation and restoration treatment processes employed in the restoration of colour photographs). To date, for the conservation and restoration of paper photographs the treatment employed in the paper has been employed without taking into account the effects that this treatment might cause on the photographed image. In this vein, the UPV/EHU research work has two main objectives: on the one hand, the study of colour or illuminated photographs and, on the other, the search for and subsequent application of suitable techniques of conservation and restoration that do not damage the photographed image. To this end, in the first place it is necessary to know the historic context of these photos. Likewise, as regards the conservation and restoration of any work of art, it is essential to know the material structure of the work before intervening and, in order to respect the suitability of any treatment or technique thereof. This is why Ms Artetxe studied the properties and material structure of the colour photographs. Also observed was the deterioration suffered by these photos. Finally, the author focused on the suitability of certain treatment processes. To carry out the research work, in the first place Ms Artetxe undertook a review of the literature. Simultaneously she located the colour photographs. Then, based on these data, she carried out the historical and material study of the pictures. After gathering this information, she initiated the experimental part. In this vein and before beginning the study of treatment suitability, Ms Artetxe analysed the effects caused by these treatment processes on the colour photographs, both on silver — colour photographs can have a silver-photographed image — as in pictorial layers. Moreover, on many occasions, especially when the photograph is highly coloured or illuminated, identifying the photographed image is no easy task. In order to measure the intervention produced the researcher measured the changes of colour and density caused by the treatment processes. According to Ms Artetxe, the results obtained will guarantee efficacious treatment processes and avoid the use of inappropriate ones. Ms Enara Artetxe Sánchez (Bilbao, 1981) is a graduate in Fine Arts. The leaders of her thesis were Marta Barandiaran Landin and Ms Itxaso Maguregui Olabarria, from the Department of Painting at the UPV/EHU’s Faculty of Fine Arts. She is currently working as a restorer.