Stoning of Saint Stephen

  • Stoning of Saint Stephen

    The Stoning of Saint Stephen, mural painting from the church of Sant Joan de Boí, around 1100, presents a lack of cohesion of the pictorial layer, with small specific losses and a stretching of the fabric that crosses the support. The tension that the pictorial stratum has, produced by the different products that have been applied over the years, provoked the instability of fragility of the painting. It is the first complete restoration of a transferred mural, with the research of new materials to elaborate the neutral colours - the areas without colour.


    The antiquity of the original materials of the work, the restes which were added in a timely in surface and the tension caused by the thickness of the neutrals, where one of the factors that caused the inestability of the delicate condition of the painting, which suffered small losses.


    The decision to intervene the work was taken because of these pathologies, following the process explained below.


    Restoration by Mª Teresa Novell and Paz Marqués, with the colaboration of d'Anna Carreras and Àngels Comella.






  • Infrared reflectography

    With the technique of infrared reflectography it could be seen some underlying lines which with visible light were seen tenuous. There are underlying brush-strokes observed in different areas that could be sketches of the painter made at time of consider the different elements. Also, these brush-strokes are observed in the area where appears the light of God, which is framed by two lines.


  • Study of fibres

    The study of the canvas provides information about a transfer of a mural painting that has been carried out in earlier times. Normally, the canvas which were used were in cotton, and the only way to verify it is through the analysis.

    In this image we see a fiber torsion characteristic of the cotton. Therefore, we find that the warp of the second transfer canvas that was used is cotton.

    Details on 40x magnification with the microscope.

  • Study of the patterns used by the artist

    The artists of mural paintings used to realize patterns to draw their characters. In the Stoning of Saint Stephen it has been studied the faces of these figure and, as seen in the image on the right, it is obvious that there is a pattern that was repeated.


    The three faces of the executioners, for example, are equal. Each one is respresented with a different color. The painter only changed the inclination of the head, the eyebrows or the hair.


    All heads were overlaid by computer to verify the similarities and differences between them.

  • Removing the neutral colours

    With the removal of the areas with neutral colours of the whole of the lower part, different layers appeared of between 1 and 2 mm, which ended up flattening the original painting.  The different layers are of very varied nature (animal glue, whiting, pigments, different resins, etc.). which provoked the fact that the tension between the polychrome and the neutral-coloured areas became evident and had caused cracks and the raising of the pictorial stratum.  


    The methodology used is the mechanical removal with scalpel and controlled humidity with deionized water.


  • Original polychrome recuperated and fixation

    Once the neutral was removed, the perimeter of the painting was fixed with 50% fish glue in deionised water.  The disinfection of the wood of the support was carried out by injection with 3% permethrin en Chile: small holes are made along the frame in the form of a grill, each 3 cm, to provide a good penetration of the product.  The holes are filled with soft coloured wax and one is protected against insects the support was reinforced.

  • Reinforcing the support

    The plaster of the different quadrants of the support and the strips of reinforcing canvas, disintegrated and with many cracks, no longer make any effort to maintain the support tensed. So it was decided to reinforce it and the canvas was prepared to make the 72 quadrants (of 22 x 26 cm each) and 154 new reinforcements. This operation provides stability and rigidity to the painting, and makes the whole rest equally and thus avoids tensions. With a vacuum cleaner and a small trowel all the disintegrated plaster from the back was removed. With reduced animal glue and whiting the prepared fabrics are bathed in the form of a quadrant and were applied to each grid of the back of the support. When the plaster was set, the piece was raised so as to ensure a homogeneous drying and tension.

    The piece now is stretched and can be cleaned.


  • Cleaning

    The piece is now stretched and can be cleaned. Mucin was used for the cleaning (enzymes from the pig’s stomach) and in specific points fiberglass pencil to remove the dirt.

  • Pictorial reintegration

    The chromatic reintegration of the small zones was done with W&N watercolours. It's a mimetic low tone reintegration. Watercolors are used because it is a painting technique in which the pigment (which is clustered with Arabic gum) is applied diluted in water and has the characteristic of being completely reversible.

  • Neutrals of large lacunaes

    To fill the large lacunaes it was carried out a study, which lasted a year and half to achieve a useful and respectful application for this big areas.

    Sands and natural animal glue was the best choice to get this vibrant result. In the right image, you can see some of the test that were made to choose the dimensions of the sand grain and the color of the mortar to treat the neutrals of these large lacunaes.

  • Final photography

    The photography once the restoration was finished.


    The Stonning of Saint Stephen is the first work of the Romanesque collection in which it has carried out an integral intervention that adopts from the support to the polychromy.


    If you want to know more about it, look up:

    Study and restoration- pdf 1,05 Mb

    La pintura al fresc pas a pas / La pintura al fresco paso a paso / Mural painting step by step (video)