Santos Juanes



Since the creation of the Restoration and Conservation Department of the Polytechnic University of Valencia, Palomino's work in the church of Santos Juanes became a subject of study. Part of the wall-burned in 1936, were uprooted and later partially resituated the vault. Its condition has no solution to the present.

The constraints that needs this work required an special intervention. Chromatic restoration of the disappeared paintings and the almost conserved fragments representing 30% of the total required an alternative approach.

Once the first phase of color reintegration was carried out, the technical and conceptual solution has become a reference worldwide. In the words of Guianluigi Colalucci, restorer of the Sistine Chapel, "The work in Los Santos Juanes has achieved a feat ".

There was graphic historical documentation, a black and white image taken by photographer J. Alcon before the fire.

Using photography as chromatic reintegration material is justified by the fact that it is an objective approach to the original artwork. This way it’s possible to avoid taking the character of a replace painting, so it’s not a fake.

But does the condition of the art have the resources necessary to implement that image on naked mortars who lived with the surviving fragments?

The answer was NO.

This is the summary of the work carried out, especially since Arsus Paper makes a commitment to solve the technical challenge posed transfer a photographic image to the uneven surface and volume of the vault, respecting the need for mortar permeability. Taking into account both, the requirements of any proposed restoration of mural paintings.

The object of all the efforts of those involved was simple, in the words of José Luis Regidor, one of the project leaders, "is attempting to return to this work, part of the appearance that made her beautiful."

The approach designed by the architects of the project, where has laid the foundations of the system can be summarized in these sections:

Consolidation and restoration of the surviving fragments.
Image processing:

- Grinding, straightening and scaling of historical photography.
- Color Management. Photography and treatment with HP Artist.
- Color for the image in B / N.

Printing and transferring the image onto the wall.
- Papelgel system.

Arsus Paper

Transferring images
Universidad Politécnica de Valencia
Departament of Restoration and
of Cultural Property

Intervention approach
Restauration of paintings
Historical image processing
Hewlett Packard

Color Management


Consolidation and restoration of the surviving fragments.

Definitive support. The plaster painting.

The principle of "similarity to the original" governing by the selection of materials used in restoration to guarantee compatibility (physical and aesthetic) and safety is one that has continued to the time of making the filling mural that was to receive the image transferred. This approach to prevail definitive nature of the support, traditional mural plaster, on the transfer system has been a challenge for the project.

First tests on the vault transfer.

For the selection of the final support for the transfer, the common pictorial plaster or filler mortars reintegration traditional for mural painting were studied, so, lime and sand mortar, plaster, etc.

The perfect scouring should just be a mortar as similar in manner and form that employ Palomino for execution of the artwork, so, a mortar of lime and sand. According to the analysis performed this would comprise lime plaster and marble dust ratio of 1/1 and 1/2 and a maximum particle size of 0.6 to 0.7.

After the evaluation and study of various proportions and variable, the decision was working with a mortar of lime and quartzite air in proportion 1/3 with a small addition of a crosslinking resin which improved tha shape of the ink reception in the transfer.


Image processing.

Grinding, straightening and scaling of historical photography.

The photograph of J.Alcón collects a particular three-dimensional space view of the dome of Los Santos Juanes. The image is shaped by several factors including the optics used, the location of the camera, the architectural form of the vault, etc. A meticulous study was necessary to obtain the correct interpretation of all this to unfold to a plane.

Georeferencing computer programs are used to locate an image in space. Basically is a match and recognizable selected points taken in the vault, which in this case would be representative points in the painting, with the corresponding photograph.

Once collected the data, and with the control points collected of the vault bound with a surveying station, are introduced into the program, the election to use the Microestation because it’s a software that introduces a sub-program that may perform both tasks as remote sensing georeferencing called IRAS_C. The processing reconstructs the image to fit the control points. Modifies elastically, positions and holds the pixel coordinates.

Intervention area of the vault.

Intervention zone.

Rectified image.

Inside of the church scanner.


software of georeferencing IRAS_C


Color Management. Photo capture and treatment with HP Artist Software.

The Hewlett-Packard has developed a tool created specifically for controlling and adjusting color digital reproduction of works of art, Artist program.
At the time of starting the restoration work the software was still in testing phase. Technicals from HP I+D Division of large format photographs worked in Barcelona to process all the pictorial set of Palomino.
The Artist system eliminates the uncertainty labor of manual color corrections.
The integration of system components such as cameras, lighting and printers, reduces the time necessary to reproduce high quality precision work. No need to regulate illuminate artwork or color correction, the software automatically solves such problems during processing.

The software performs an automatic whites balance, corrects the illumination uniformity, chromatic corrections made and generates a TIFF file with an embedded ICC profile that is specific to that particular piece of art.

Color for the image in B / N. Digital painting.

The fragment corresponding to the working area of ​​the photo in B / W of J. Alcon is expanded, and corrected, the actual size of Palomino presented frescoes in the vault, about 250 square meters.
Certainly the great enlargement makes visible the silver halide particles comprising the photographic images, making of the image near lacks sharpness. But the whole painting will be seen from the floor of the temple, 26 meters away, reducing, in turn, the proportion of the observed.

To add color to the image of J. Alcon, firstly the photographic scanning has to be overlaped with the Artist software treatment.
After adjusting the two images the selected areas of color photography and painting are not deleted. Obtained in this way two superimposed layers ready for digital colored phase in Photoshop program.

The color layer is desaturated to match and level the lights and shadows of a photograph of J. Alcon, adjusting the grayscale original photo in B / N, with respect to sweep color photography.
Taking as a reference the colors of the original painting, transparent color layers are created as a glaze-color-singing until grays.
Finally, the result is adjusted by increasing the level of detail to make the most number of pieces fit.

Assembly of the original fragments and photo in B/W.

aplication of color to the picture in B/W.

Final appearence of the image trasferred.


Printing and transferring the image onto the wall.

The technical challenge: just transfer the ink is not waterproof image to the wall.

The most important reason, apart from the desirability of the wall sweat, moisture balance inside / outside and avoid condensation, and keep it healthy, is that in the case of possible leaks inevitably dragged salts and the only way that would be available the precisely of the surface of the fragments preserved frescoes of Palomino.

The current state of the art features, with varying degrees of success, different solutions to transfer printed images, but so far to the different needs that require a mural as it has been explained maintain patency of the support.

Papelgel system.

Arsus Paper has developed a temporary support for transfer of inkjet printing. Starting from Papelgel ® Original, new development provides better control of the elasticity of the material. Furthermore, the new solid composition of the gel structure allows only the ink transfer photographic images printed on any surface, regardless of the texture, shape and porosity, without the need of special preparation of the support.

  • -PapelGel is transparent, track work is complete.
  • -PapelGel is transparent, track work is complete.
  • -PapelGel is elastic, which allows to adapt the plaster textures, irregularities of the surface of the volume and adjust the defects dimensional image transfer and ensure a correct fit.
  • -The ink-transfer requires no adhesive, so, only the ink transferred without sealing the wall bracket.
  • -The transfer is done with water, excluding harmful solvents that could damage the original work, as for operators.
  • -The remaining non-transfer compatibility between ink and lime plaster.

Transfer system with the new development Papelgel:

Papelgel impresion.

Image cropping.

Water bath.

Drained water.


Wall presentation.

Roller pressure.

Removing Papelgel.

Aspect of the work area.

After the transfer process on the wall surface only the ink remains, and is compatibility with the definitive support will determine the safety and stability of the print.

Detail of a fragment.

1st transfer done.

General appearance.

The workshop of analysis and intervention mural from the Restoration Institute of Valencia Heritage (IRP) made a detailed study of the behavior of the pigment ink transferred onto plaster wall. This is a summary of the work carried out:



Several studies support the stability of inkjet prints with pigmented inks on various substrates, but are not aware of their behavior on lime mortars, since the application is unprecedented in the world.

The solidify system required to transfer the ink Papelgel liquid originally dry, on the temporary support, is dissolved again, and finally fixed on the wall surface. This change of state or the fact that the wall surface of lime and sand for a long time maintained a strongly alkaline pH (13), are factors that could alter the stability of the whole. To resolve these doubts were conducted studies that confirm the suitability of the structure pigmented ink / plaster wall.

A large number of specimens were subjected to artificial accelerated weathering cycles (UV illumination, temperature, humidity, polluted atmospheres) and therefore comparative chemical analysis such as assessment of changes color difference (DE *) and brightness were satisfactory, being for example more weakness in the wall bracket in the inks in the case of contaminated atmospheres test.

On the other hand, a comparative test was performed to check the abrasion resistance, which allow assessing how the structure reacts to factors such as erosion, friction, etc. The conclusion was that transfers generally have moderate resistance to abrasion compared to a fresco painting surface made, but very similar even carried over to dry surfaces with watercolor, which is the most used in restoration.

Chemical resistance test found that the transfers are sensitive to high polarity solvents such as toluene, and to a lesser extent to water.
The oldest specimens, two years old, had the highest chemical resistance to the most recent, 3 months, that is, due to the gradual hardening of lime mortar as the binder curing inks, chemical resistance of transfers increases with time.

Conducted sponge contact absorber tests confirm objectively that the ink transferred is not a barrier to the natural breathability of lime and sand plaster.
The methodology of the contact sponge-developed by CNR-Florence-ICVBC has been proposed as a simple and fast method to evaluate "in situ" the effectiveness of a water-repellent treatment on stone surfaces.
The method is based on differences in weight according to the formula:
Wa (g/cm2. Min) = (Pi-Pf) / 23.76 x t
Where (Wa) is the amount of water absorbed during the test.

































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