1As conservators, we had the chance to work on two featherwork pieces : the triptych of the Musée de la Renaissance in Ecouen (near Paris), and the Mass of St Gregory from the Musée des Jacobins in Auch (south of France). The two museums wanted to exhibit them. Because of the exceptional character of the triptych, the Director of the Musée of Ecouen whished to have a precise study of the fabrication techniques, in order to help the restoration choices. For this, a multidisciplinary team was formed, with scientists, art historian, curators and 4 conservators of different specialties : painting structure, ethnography, paint layers and wood. We went to Vienna, to the Museum für Volkerkunde for a study visit in order to look at other featherwork pieces and their condition. The association of a painting structure restorer and an ethnographic restorer to look at the featherwork was, in our sense, essential, as it allowed a complementary vision on the problems and solutions, with 2 different approaches.
2The Mass was restored after the triptych, and all the work done before was very useful as they seem similar in terms of techniques. The 16th century triptych, of Mexican origin, is decorated with a religious scene showing the Crucifixion on the middle panel, with a female bird feeding babies on the top of the cross ; St Jérome, hermit, on the bottom right and St François d’Assise on the left. On the left panel, Mary in front of Jerusalem and on the right panel :St Jean. The back of the side panels is covered with hide, decorated with an animal glue painting a tempera. We can more or less observe that there was 2 characters, but it is hard to say if they were Saints or Apostles. The back of the central panels is also covered with hide, but not painted, and is reinforced with 3 wooden pieces. The triptych is 67 cm high by 93 cm wide, when it is open. Different types of analyzes were made, going from simple observation by specialists to laboratory analyzes. We learned many things. The 3 panels are made from resinous wood origin. The 3 crosspieces, added to reinforce it, are made from oak. The resinous wood had been infested after it was used as a support for the feathers, as we can see holes through them.
3Metallic bent wires, going through the wood, are used as hinges to insure the mobility of the panels. The question was raised if the triptych was an old one, brought to Mexico and re-used, or if the different elements had been imported and the wooden triptych made in Mexico.
4Concerning the featherwork : feathers have been stuck, always in the same direction, on a non-woven vegetal fibres support, made probably form amate and sisal. Analyzes showed also evidence of cotton fibres. The glue used is rich in starch grains, and was from orchid’s origin.
5The whole form panels of different colours and shapes, used to create the scene. Those panels are then applied on the wood, from the top to the bottom of the work. The feathers are always presented vertically.
6Some details like eyes of characters or architecture elements are underlined with black. For this object, we are still unsure of the systematic use of black feathers, or if sometimes, some black material, like ink or dye for example, has been used. It is different for the Mass of St Grégoire, that we will se after.
7Some elements are underlined with gold ribbon (like the borders of Mary’s dress for example).
8Some elements are made from gold, like the moon. The X-Ray shows the places were they were attached. For this, holes, under half a millimetre size, have been pierced in the gold. Those elements are then sawn to the vegetal support and the feathers cover the pierced parts.
9The feather colours were very diverse and bright, and the frame was also painted with bright colours like blue, red and yellow.
10The visual impact was probably in contrast with the external painted surfaces on hide.
11It was not possible to determine the hide nature, but it was prepared with European techniques. Only the side panels were painted but many parts are today missing.
12The Mass of St Gregory was made in 1539. It is 68 cm high and 56 cm wide. We can identify St Gregory. JC appearing miraculously, surrounded by the passion symbols. All the elements are copied from occidental symbols, except the pineapples which are the only exotic elements. The back of the wooden panels has a monogram painted.
13Some areas with missing feathers show the non-woven vegetal fibres support. The feathers are again organized vertically. In this piece, we can see that some of the designs are underlined with black lines due to superposition of feather pieces. In fact, some missing feather layers show the evidence of use of black feathers, partly hidden by coloured feathers.
14It seems that, in some other cases, such as blood on JC breast, dye or paint has been used.
15Here again, the elements are organized on top of each others. It is really remarkable when we look at the breaking light picture. Here, gold doesn’t underline shapes or elements. It seems, but it is an open question, that some elements could have been originally made with gold, such as helmet, blade, coins… that are today all made with filling material. The only gold elements are the stars.
16Those objects were the subject of detailed condition reports, illustrated with detailed drawings. As they are heterogeneous objects, made from a diversity of organic materials, they suffered from a variety of behaviours to the different agents of deterioration, such as inappropriate environment, light, dust, insects, but also human habits, bad handling, and inappropriate restorations.
17We decided to classify the degradations depending on their origin.
18Considering the environmental agents of deterioration in the case of the Ecouen Triptych, and as the different materials were heterogeneous, many mechanical solicitations happened through all the layers of the work.
19Due to variations of relative humidity, the wood expanded and retracted. As the vegetal fibres support was sticked on the wood, it finally cracked following the grain of the wooden panel. Severe cracks were observed, often open with lifted edges.
20We can observe here also some parts where featherwork is totally missing.
21The vegetal support came off in some places, due to combined action of movements of the wooden panel, and lack of adherence of the glue, maybe partly due to ageing. It is visible in breaking light, where the deformations appear clearly.
22We could also observe that in many places, feather layers were detached from each others. This was again due to a combined action of climate and ageing of the glue, probably accelerated by the action of light. The same result was found for the hide on the external sides, which was lifted in some places.
23Variations of climate could partly explain the condition of the painting on the panels.
24Feathers were naturally coloured or died sometimes. Light energy and UV discoloured some feather colours such as red, pink and yellow, as we could observe by looking at hidden feathers. The brownish aspect in some areas could also be the result of discoloration.
25Finally, the surface was very dirty and darkened. The colours were dull and the legibility of the drawing was bad.
26Only a few insect holes could be seen, due to old infestation. It’s interesting to note that it was xylophage insects that were attracted and not moths.
27In the case of the Mass of St Gregory, it had been restored 10 years ago to reinsure the adherence of the layers to the wood panel.
28In this piece, no deformations were found as in the Triptych. But we could again find cracks, more or less severe, areas with missing feathers, lack of adherence of the feathers layers from each others, and signs of old infestation. For example, it seems that there was probably a third pineapple, which disappeared due to insects.
29In the case of Ecouen Triptych, it seems that its use was quite intense. Due to handling and touching, we can observe local abrasions of the feathers.
30Some elements of gold were bent.
31One of the hinges was dislocated and the result was that the piece of wooden frame just next to it felled. It is missing.
32Then again the hide is lifted due partly to human use.
33If we look at the condition of the external paintings, we can observe that many parts are missing, particularly around the hinges, due to inappropriate handling.
34The Auch piece doesn’t seem to have such type of degradation, however the presence of many gap fillings was a question for us that we will develop now.
35We classified hem as agents of deterioration as we can observe that they affect the aspect of the featherwork.
36For the Triptych, some inpaintings on fillings show that this former restoration was done the same way as for paintings on canvas. So the specificity of the featherwork seems not to have been taken into account. Laboratory analyzes found that the pigments used were synthesized from the beginning of the XIXth century and offer a starting datation for those restorations.
37In some places, the fillings and inpaintings cover the feathers and hide some details. The legibility was very difficult as they were very present and visible.
38Traces of adhesives, brown and shiny, were visible on the surface of the feathers, due also to old restoration.
39The wooden frame was totally repainted, as we could see in some places the original and bright colours.
40In the case of the Auch piece, we can also observe some gap fillings. The question is open to know if they were made to replace the gold elements that could have been lost or stolen, or if it was like this since the origin of the piece.
41In other places, the fillings were made to replace lack of feathers. But it is always different from the Triptych, as they never cover and hide feathers or elements.
42For the Mass, which was in sound condition, a simple consolidation of the feathers that were lifted was made in order to insure that the artwork could travel and be exhibited safely. As well, a light cleaning was made.
43For the Ecouen piece, the objective was to give back the legibility to the artefact, showing its technical and esthetical specificity, as well as respecting its material history. It was also essential to insure its future conservation.
44First ; the question of cleaning was crucial. As we wanted a minimal intervention, it was difficult to decide the level of cleaning. The trip to Vienna, and the viewing of “clean” pieces, with shiny feathers, decided us. We were then happy to have this choice confirmed, during the visit of Alessandra Russo and Serge Gruzinski, as they told us that the iridescence and brightness of feathers are essential as they are the sign of “sacred”.
45Second : we had to solve the problem of cracks. We stuck the vegetal support back to the wood with starch paste, as it’s nature was similar to the original materials.
46We decided not to treat the problems of deformation. In fact, we thought that it was irreversible. By sticking back the vegetal support, we would have create new tensions and possibly new cracks.
47Third: we stuck back the lifted feathers to the vegetal support with a cellulose based and mat adhesive.
48Fourth : the gold elements, that were bent, were flattened back and stuck with a powder adhesive re activated with heat.
49Fifth : the leather was stuck back and the hinge and wood piece remade.
50Sixth : all the in paintings were removed and a collective decision was taken to leave those areas free. It seemed more appropriate to use the light properly in order to highlight some parts and hide some others.
51We finally insisted on preventive conservation measures that should be taken in order to avoid major restoration in the future, like appropriate and stable climate, control of light levels and UV, exhibition choices…