The idea to organize the workshop as well as to create and publish an handbook of the course was materialized by the determination of Escola Artística e Profissional Árvore to develop initiatives to disseminate Conservation with international character. This event was also inspired by the PhD investigations by Ana Bailão, in collaboration with Sandra Sustic, focused on the retouching criteria.
The workshops started with the two-day workshop of mimetic retouching held by Croatian conservator-restorer Sandra Šustić (Croatian Conservation Institute), at Escola Profissional e Artística Árvore, on 21st and 22nd of June 2013.
In the second year, on 27th and 28th of June 2014, Amelia Vela, conservator of gilded and polychrome wooden objects from La Fundación de la Comunitat Valenciana La Llum de les Imatges, Valencia, held also a two-day workshop, this time about retouching gilded surfaces. Theoretical and practical classes were done and new techniques of retouching gilded surfaces were demonstrated.
In 2015, Leonardo Severini, easel paintings private conservator established in Rome and lecturer in Universities of Urbino and Viterbo, in which he carries out his particular interest about retouching and different solutions of presentation, held on 26th and 27th June, a workshop about retouching with Italian techniques. His knowledge about the techniques practice in Rome and in Florence was very important to demystify the tratteggio technique. Demonstration in mock-ups and in real artworks were fulfilled.
In 15th and 16th of July 2016, Francesca Tonini, Graduated in the Restoration of Canvas and Easel paintings, and Wooden sculptures at the Centro di Restauro di Villa Manin di Passariano (Udine – Italy), graduated in Conservation of Cultural Heritage at the University of Udine, Author of the book: "La scultura lignea tecniche e restauro. Manuale per allievi restauratori"with preface from Giuseppina Perusini. Francesca Tonini is a member of ICOM-CC, and part of Sculpture, Polychromy, and Architectural Decorations Working Group. Theoretical and practical classes will be done in this two workshop days at Seminário Maior of Porto
In 2017, Sandra Sustic and Ana Bailão, held on 6th May, a workshop about retouching. Demonstration in mock-ups was fulfilled to try new materials and new techniques for retouching Old Masterpieces and Contemporary works. Theoretical and practical classes were done at Portal de São Domingos workshop.
On 26th and 27th of October 2017, Roberto Bestetti, during the two days course prepared two colour palettes with hand grinding binders and pigments. The colours produced can be usefull to those who carry out interventions on ancient, modern and contemporary artworks. The RECHGroup collaborated with the Portuguese contemporary conservation studio - 20|21 Conservação e restauro- and the support of Escola Artística e Profissional Arvore.