The restoration of paintings on canvas

The restoration of painting on canvas sometimes requires the use of the technique of re-lining or lining the original support. This was the case of a set of paintings on canvas in a restoration campaign in the parish of San Pablo in Zaragoza (2006-7) sponsored by Cajamar and the parish of San Pablo in Zaragoza.

THE WORK. ICONOGRAPHY

The restoration of paintings on canvas, normally oil paintings, has a traditional procedure when the original support is one of the causes of deterioration of the works. In these cases, the traditional lining with flour and animal glue porridge has been a resource to solve this type of problem.

San Blas is paired with San Gregorio and both are hung in the archives office of the Church of San Pablo in Zaragoza. Dimensions are similar (173 x 142 cm), current dimensions are not original dimensions. At an unknown date, the two previous paintings were cut at least 4 inches to match their current frame. Thus, both figures suffer mutilations in the upper area of the head, corresponding to the headdress.

Both works, oil on canvas, are framed in the painting of the second half of the seventeenth century, as is clear from the clothing of some of the figures in the composition, which clearly dates from that time. They are paired by default, since the compositions revolve around the figure of the saint, coinciding both in ecclesiastical rank and in the cult processed at a popular and geographical level, in which the most representative episodes of his life are related. (Miracles and martyrdom).

At the end of this publication there is a small biographical review of these two saints.

 

STATE OF CONSERVATION

As explained in the previous section, both paintings have undergone drastic changes, both in their original measurements and in some of their compositional details. To adapt them to certain frames, at the time they were cut both in their upper and lower edges, that is, in the length of the painting. Likewise, after doing this, they varied the composition of the works, covering the mitres of the characters, which after the cut were cut, with a repaint that imitated the heads and hair of the characters to include the entire figure within the framed work.

This is the main and most important alteration confirmed by both works, since it is irreversible in terms of size, although the usual deterioration of time and regular conservation have also been observed in this type of works; cracking of the pictorial layer and many small losses, progressive loss of adhesion of the paint, among other reasons due to the lack of tension of the support that in this way becomes more mobile and malleable, and in general generalized darkening of the surface layer by the oxidation of the various varnishing and patina applications.

TREATMENTS PERFORMED

Documentation

Before starting the restoration process, all damages to the works were documented both photographically and literarily. During the entire restoration process, the most significant features were photographed.

Mechanical cleaning of the textile support

Of the different possibilities of treatment of the support, it was decided to wrap the canvases by means of the traditional procedure of lining with flour gacha, a procedure unified by the characteristics of both works, their size and type of alteration (deformations, tears, rips, sevens and lack of support).

For which, the necessary infrastructures were installed to carry out the process in a continuous and systematic way, leaving the subsequent processes of restoration of the complex (aesthetic restoration, cleaning and reintegration of the pictorial layer) for a later phase. A manual (Spanish) loom (180×150) was used, which was precisely adapted to the size of the work.

Before starting the treatment, the paint was protected. The old frame had been first removed (it had no wedge system), unlocking and stretching it, clamping the original canvas with staples on a rigid horizontal surface. The protective paper was adhered with animal glue and Japanese paper.

This allows, with the painted face protected, to clean the back of the work, the fabric itself with a shallow and homogeneous sanding of the entire surface of the back to eliminate irregularities (boliches, knots, remains of primer, etc.); the original seams were preserved by removing the excess without affecting their function.

Lining

All these procedures prior to the lining of the original canvas, were necessary for a good adaptation of this to its lining, which also had to be prepared with an exhaustive “wear” of the new fabric; The purpose of this is that the new fabric loses strength and does not have contraction and expansion movements in the future that could affect the work once it has been restored. This was done by tensioning it on the loom and wetting it in successive actions until the new fabric showed no movement and, when dry, it was as taut and stretched as it was wet.

The fabric used was Belgian taffeta linen, with 15 warp pitches per square centimeter of weft, which best suited the average characteristic of the two original canvases and was thick enough to retain the adhesive and expel excess.

The amount of adhesive (flour with animal glu gruel) applied varies depending on the problem of the pictorial layer, being necessary more if you find excessive paint peaks, also linked to a greater deformation of the support. Flow control and heat do the rest. For the rest, the mechanical process of ironing, drying and moistening when necessary, is similar in all cases, although a greater amount of adhesive and size corresponds to a greater working time and spacing of the processes.

After the completion of the lining and drying of the work, after removing the protective wallpaper, the new frame, with a wedge system, was placed, something essential for the stretching and stress control of the work in the future.

Cleaning

Cleaning process: 3A was used for general cleaning, removal of rusty varnishes and accumulated dirt. The head repaints that covered the headdresses of the saints were removed by applying acetone gel compresses, stirring and neutralizing with 50% Ethanol in White Spirit and acting mechanically with the tip of a scalpel, going over with 3A to eliminate residues and homogenize the cleaning.

Material and chromatic reintegration. Final protection

The most significant faults were revoked with stucco, (animal glue and lime sulfate) and later the polychromed lagoons with watercolor. With dotted and “regatino” were reintegrated according to their dimensions, and finally a varnish layer was applied for protection. Finally, it was varnished with touch-up varnish to adjust. And later with a final varnish with a brush and two applications with spray: a first application of 50% dammar varnish in the essence of turpentine to regulate the reintegration. At last final varnish with shiny dammar varnish applied to brush and final spray with the same varnish.

Biographical review

San Blas

This saint (year 316) was bishop of Sebaste, Armenia (southern Russia). At first, he practiced medicine, and took advantage of the great influence that his quality of excellent doctor gave him. So he speaked to his patients in favor of Jesus Christ and his holy religion, and thus obtain many followers for Christianity. Knowing his great holiness, the people elected him bishop. When the persecution of Diocletian broke out, Saint Blaise went to hide in a cave in the mountain. And from there he led and encouraged the persecuted Christians and at night he sneaked down to the city to help them and help and comfort those who were in prisons, and bring them the Holy Eucharist.

They cut off his head (it was the year 316). And after his death, he began to get many miracles from God for those who prayed to him. He became so popular that in Italy alone he had 35 temples dedicated to him. His country, Armenia, became Christian a few years after his martyrdom.

San Gregorio Ostiense

He is known as abbot of the monastery of San Cosmas and San Damiano, in Rome. Pope John XVIII appoints him bishop of Ostia and later elevates him to cardinal, becoming an Apostolic Librarian, where he served for four popes.

It seems that he arrived in Spain in the first half of the 11th century. He went as a papal legacy before the Cortes of Burgos and Pamplona. His sending from Rome probably had to do with issues related to the ecclesiastical organization of Spain at some point. Because it was very necessary to determine the boundaries of the dioceses. It was the origin and source of numerous conflicts and not only due to interference from the episcopal jurisdiction. But also for belonging to different sovereigns. So this involved negotiations with interested kings and bishops, and for this work a man with political tact and great ecclesial sense was needed.
And he lived about five years in Spain.

Exhausted and ill, he retired to Logroño where it seems that he died around the year 1044; but his body is venerated in the church of San Gregorio de Pinave, between Viana and Logroño. It is said that he once freed the Riojan fields from a plague of animals. And that is why the farmers invoke him in a special way against lobster.

• churchforum.org
• Autor: Archidiócesis de Madrid| Fuente: Archidiócesis de Madrid. catholic.net/santoral/articulo

For more information on this topic:

Lining a painting on canvas