Croatian Conservation Institute launched in 2010 a comprehensive programme of completing the renovation of the Gothic choir stalls from the Cathedral of St. Anastasia in Zadar. Richly decorated, originally painted in vivid colours and gilded, the stalls have throughout history been subject to numerous restorations and alterations according to the tastes of the time. The last treatment was initiated in 1969, at the then Conservation Institute of Croatia, but due to the lack of funding it was suspended as early as 1972, and the semi-restored parts were stored in a depot. The article brings results of the recent conservation research which provided information about the original appearance of the choir stalls, a review of previous treatments and a description of the works performed at the Croatian Conservation Institute in the last three years.
History and alterations
The Gothic choir stalls in the Cathedral of St. Anastasia in Zadar were commissioned in 1418 by the Zadar Archbishop Luka Turriani of Fermo and executed by the Venetian woodcarver Matej Moronzon,, son of carver Andrija, who subsequently settled down and continued to work in Zadar. The choir stalls took a long time to complete, until as late as around 1450, so aside from the Archbishop Turriani’s coat of arms, they also included the coats of arms of his successors, Blaž Molin, Lovro Venier and Maffeo Vallaresso. The name of the painter who painted and gilded the stalls is unknown, but it is assumed to be that of Master Ivan Petrov of Milan, with whom Moronzon had previously collaborated when carving the high parapet in the cathedral – between the presbytery and the church nave, with the sculptures of the Crucified Christ with Mary and John and the twelve apostles, modelled after those in the basilica of St. Mark in Venice. The parapet was commissioned from Moronzon in 1426 and removed not later than the early 16th century, after which the sculptures were relocated around the church. The still existing statues of Christ and ten apostles underwent conservation in the Conservation Institute of Croatia, from 1968 to 1972. Nowadays they are displayed at the Permanent Exhibition of Church Art in Zadar, while the sanctuary of the cathedral keeps a replica of the crucifix.
Owing to the importance of the Zadar Chapter and the great number of its canons, the choir stalls are very large and have as many as 54 seats. A single seat on each side is larger and more richly decorated than the rest: the Archbishop’s seat on the northern and the Duke’s seat on the southern side. As indicated by conservation research, the stalls had originally been painted in vivid colours and richly gilded, so even the back sides had been decorated with mouldings and painted. On the curved part above the seats, there used to be decorative carved grids, with 42 old parchment leafs laid behind them, dating from the 12th, 13th and 14th century. The parchments torn off from the books of sheet music, novels in Old French Language and old books of hours had been re-used as a vivid background for the carved grids. In 1969 they were dismantled and conserved at the Conservation Institute of Croatia and are nowadays kept at the Benedictine Convent in Zadar.
Throughout the centuries the stalls have been renovated on numerous occasions. As the stratigraphic analysis undertaken as part of the conservation research has revealed, they have been re-polychromed at least twice. The first such occasion was probably in the late 18th century, when he stalls were moved apart towards the arches on the sides, as part of a major interior renovation effort, which saw the triumphal arch constructed and the sanctuary vaulted and opened up with large windows. Nowadays a later-date, second re-polychromy is visible, which was executed between 1883 and 1885 by Oscar Marcocchia of Zadar, whose signature is found on the back side of the relief bust of God the Father, located above the Archbishop’s seat. The partitions between three eastern seats of the northern wing and five seats of the southern wing have been removed, and many lost ornaments have been replaced. Large surfaces were repainted in single-colour dark-brown glaze, while only the figures and a smaller portion of the decorations were gilded and painted. At the same time, the back sides of the choir stalls were partially hacked off and then walled up, only to be re-discovered in the conservation effort that was undertaken from 1969 to 1972 by the Conservation Institute of Croatia.
Between the two world wars, during the Italian rule, major conservation efforts were carried out in the interior of St. Anastasia Cathedral. The Italian conservation authorities from Ancona removed the Baroque additions in an attempt to represent a Romanesque building, of whose appearance they had but insufficient knowledge, which resulted in what is, to a large extent, a free interpretation. Those portions of the choir stalls that stood closest to the church nave have thus fallen victim to the effort, as once the triumphal arch had been removed and pilasters with half-capitals constructed, there was no room left for them. One relief above the southern door, which carried the busts of prophets Malachi and Zechariah, was at this time removed and had remained stored for almost seventy years. Between 2010 and 2013 it finally underwent conservation at the Croatian Conservation Institute and was returned to the console on the northern part of the sanctuary, on the right-hand side next to the choir stalls.
Conservation research and treatments
Parallel to working on the relief, other conservation treatments were performed at the Croatian Conservation Institute, both on the choir stalls in situ and on the parts that had been dismantled during the previous conservation effort from 1969 to 1972. These were later stored, as the work was suspended after the programme ceased to be financed. Specifically, it was the carved grids with the parchments located behind them, the bust of God the Father from the Archbishop’s seat back and other smaller decorations. The treatments carried out at the cathedral itself were primarily directed at consolidating the structural and decorative parts. As the seat backs were leaning to the front, they were tightened to the arches with steel braces. Unstable parts of the structure and ornaments were consolidated, and those that had fallen off in the course of time were returned to their original position.
Microscopic and macroscopic examinations indicated that Moronzon had used different kinds of wood, depending on each part’s designated use. The structural parts were made from conifers, mostly larch wood, the smaller carvings from linden wood, the sides of the seats and a portion of the larger carvings from walnut wood. XRF analysis of the pigments of the 15th-century polychromy revealed that the blue paint had been prepared with ultramarine and lead white, the green with auripigment and ultramarine, and the red with vermillion and lead white. Using FT-IR and thin-layer chromatography, a protein-based binder was identified, as well as a mixture of natural terpene resins and oils. It had probably been a glue paint, protected with an oil-resin coat in the final layer. The analyses were performed only on those surfaces where paint and oil gilt had been applied directly over wood, without a base. Samples for laboratory analysis were not taken from the sculptures, as these constituted only a small portion of the ensemble. However, when examined under magnification, it was revealed that the painting technology that was used was more expensive and more challenging to execute – a white base is present, the gilt is polymentic, and the paint binder is not water-soluble, indicating that it is probably emulsive.
As the binder of the black coat over the ornaments and the flat parts had pulverized, the impurities were removed using dry procedure, Wishlab sponges and a soft brush. The oil paint and the polymentic gilt on the figures were cleaned with aliphatic (paraffinic) solvent. Dark stains from corrosion in the wood were lightened using a firm gel - Phytagel with EDTA, pH 8.5. The wood that was falling off was consolidated with polyvinyl-butyral, brand name Mowital B30 H15, solved in the 10% solution of ethyl alcohol. The paint was consolidated with 5% gelatin, some portions additionally with Plexitol 500 acrylic dispersion and the 5% water solution of water-soluble Aquazol polymer. Non-structural parts that required no resin consolidation were glued with the cold collagen Titabon glue. Missing parts of the wood were reconstructed in balsa wood, linden wood or putty, depending on their location and size. Individually located elements that have been completely lost were made from linden wood, as well as the projecting parts which are exposed to injuries and wear-and-tear, while balsa wood was used to reconstruct the elements partially preserved, in addition to those that are better shielded from injuries. Missing parts of the apple were carved from walnut wood. Tiny injuries to the wood were filled with PVAc glue putty, Gesso di Bologna, fine sawdust and micro-balloon.
The damage to the polychromy in the dark portions of the relief with Malachi and Zechariah was covered with the base of 6% glue, toned umbra and grape black. The wood was covered with a single thin base layer in order for the details of Moronzon’s carving to remain recognizable. As opposed to that, the injuries to the figures and the gilded parts were filled with a 6% chalk-glue base up to the level of the re-polychromy, and ironed. The damaged gilt was reconstructed in gold leafs bound with acrylic mixtion. New parts of the wood, putty and the new base were retouched, first in watercolour and then in urea-aldehyde Gamblin paints, solved in ethyl alcohol. The surface was varnished with the 15% varnish of hydrogenated carbohydrate Regalrez 1094 resin, solved in Shellsol T, a paraffinic solvent.
 Ivo Petricioli, Umjetnička obrada drveta u Zadru u doba gotike, Zagreb, Društvo historičara umjetnosti Hrvatske, 1972. The publication issued all known contracts with Matej Moronzon, pertaining to his work in Zadar.
 Emil Hilje,Umjetnička baština Zadarske Nadbiskupije. Kiparstvo od 4. –16. stoljeća, catalogue, (ed.) Nikola Jakšić, Zadar, Zadarska Nadbiskupija, 2008, 234.
 Ivo Petricioli, Katedrala sv. Stošije, Zadar, Zadarska Nadbiskupija, 1985, 18.
 Ivo Petricioli, Stalna izložba crkvene umjetnosti Zadar, Zadar, Stalna izložba crkvene umjetnosti Zadar, 1980, 96-99.
 Katalog radova Restauratorskog zavoda Hrvatske 1966–1986, in: Godišnjak zaštite spomenika kulture, 12 (1986), Zagreb, Republički zavod za zaštitu spomenika kulture, 117; Archives of the Division for the Immovable Heritage of the Croatian Conservation Institute, Zagreb, Report on the conservation of choir stalls from the Cathedral of St. Anastasia, Zadar, St. Anastasia, choir stalls, file no. 15/1, 1971.
 Pavuša Vežić, The Episcopal Complex in Zadar, doctoral dissertation, Zadar, University of Split, Faculty of Philosophy in Zadar, 1993.
 Margareta Klofutar, Laboratory report 75/2013, Zagreb, Natural Science Laboratory of the Croatian Conservation Institute, 2013; Margareta Klofutar, Laboratory report, Zagreb, Natural Science Laboratory of the Croatian Conservation Institute, 2010.
 Domagoj Mudronja, Laboratory report. Investigating pigments from a choir stall of the Cathedral of St. Anastasia in Zadar, Zagreb, Natural Science Laboratory of the Croatian Conservation Institute, 2012.
 Marija Bošnjak, Binder analysis report, 2010; Marija Bošnjak, Domagoj Mudronja, Binder analysis report, Zagreb, Natural Science Laboratory of the Croatian Conservation Institute, 2011; Margareta Klofutar, Laboratory report 34/2013, Zagreb, Natural Science Laboratory of the Croatian Conservation Institute 2013.
 Mirjana Jelinčić, Laboratory report 58/2013, Zagreb, Natural Science Laboratory of the Croatian Conservation Institute, 2013.