Reliquary: The Assessment and Remediation of Structure and Cosmetic Concerns

By Ann Kennedy Haag, Chief Conservator of Frames, Gilding, and Furniture

Testimonial From Client:

“In Ann’s skilled and patient hands the reliquary was preserved and its beauty restored. Preservation is not a lost art as evidenced by the expertise of the Chicago Conservation Center. We are “floored” with the end result of our piece and look forward to appreciating its beauty in our home. We thank you Ann and The Conservation Center!”


(Above) Crated Reliquary as it came to The Center

A Belgian Dutch style Reliquary, likely crafted in the 17th century, housing numerous religious relics, and exemplifying two distinct decorative paint styles, came to The Center in need of conservation and structural support. Of initial concern was the broken glass over the large central reliquary shadow box. The top third of the broken glass section had fallen into the box. Upon further examination two additional concerns arose: the structural stability of the case overall, and of the top decorative paint layer.

(Above) Pre-treatment: Broken glass on the central shadow box

The glass for the central shadow box had reportedly been replaced in the past, yet continued to break. Investigation of the rabbet indicated that the glass had been placed under uneven pressure and the rabbet was not level, therefore the glass easily broke when strained. The glass was held in place with pressure from the shadow box, which was set into the rabbet from the verso. The unevenness of the rabbet caused additional stress that readily fractured the glass. Accretions, non-original material, causing the unevenness of the rabbet and creating pressure points were first removed. The broken glass was then adhered at the break line with a reversible clear adhesive. A piece of acrylic UF3 Plexiglas with UV filtering was cut and placed between the glass and the shadow box.

Scrutiny of the reliquary case revealed that, some time in the past, there had been a serious and likely long term insect infestation of the wood. Additionally the wood, due to its age, was dry and brittle. Wood boring insects live in the wood as larva, burrowing and eating the cellulose fibers. As adults, they bore up to the surface of the wood and leave the structure; the hole they leave open is called a ‘flight hole’. Interestingly, insects do not like to eat paint or other decorative elements, such as gesso, the ground beneath gold-leaf. They will burrow just beneath the surface, leaving a shell of paint or gesso above them until they reach an undecorated area or have no choice but to burrow through the paint or gesso layers. This leaves a very fragile decorative shell that is easily fractured. Most flight holes may be found under, behind, or inside undecorated compartments of cases and frames. Consequently, it is often not immediately evident that an item has insect damage. The reliquary had several areas of severe damage and other areas with less severe damage.

(Above) Detail: Flight holes and dust

This photograph shows an entire fragment that has been lost due to severe insect damage. Note also the ‘dust’ on the white packing material; this is called ‘Frass,’ and is typically the first evidence of an insect infestation. In order to give the dry, brittle wood additional stability, a conservation consolidant was injected into the flight holes and broken portions of the case. The consolidant saturated and hardened the wood, giving it increased structural stability.

Two generations of decoration cover the Reliquary. The first and earliest consists of ebonized wood and gilt passages as was typical of 17th century Belgian and Dutch cases and frames. The later decoration is faux marble and gilt. Many of the original gilt passages were over-gilded or gold painted, and all of the ebonized passages were changed to a faux marble appearance. The first generation, the ebonized surface, was in very good condition; however, the later faux marble decoration was delaminating and flaking off the surface. Here, the conservator identified two options for treatment: either remove the later layer of paint to reveal the original decorative surface, or treat the current paint as part of the history and character of the piece. There were portions of the wave molding that over time had been replaced with various compositions of varying degrees of quality. None of the replaced moldings would be visually acceptable if the distracting later paint was removed. The later paint was likely added sometime in the mid – late 18th or early 19th century, and was therefore quite old. These factors helped guide the decision to retain and preserve both the early and later paint layers.

(Above) Detail: Delaminating and flaking finish

Solvent testing was necessary to determine an appropriate consolidant. Factors used to determine appropriateness included reversibility, as well as potential damage to the original decorated surface should removal of the later paint be deemed necessary at a later time. To stabilize the paint layer, the chosen consolidant was carefully injected between the delaminated paint layers, and minimal pressure was applied to join the surfaces. This required many hours of patient and tedious work with the fragile and brittle paint.

After treatment was completed, a mount was custom-fabricated to the exact dimensions of the reliquary to provide protection and general structural support for the piece. The mount was essential in attaching the case to the frame.

The treatment resulted in the stabilization of the Reliquary, as well as enhancing the beauty and uniqueness of this important, historical piece of art. Not only was the treatment challenging, it was extremely rewarding to work on a piece of this caliber.

(Above) Detail of custom built mount

(Above) Post treatment