Elizabeth La Duc gave an engrossing talk in the Objects Specialty session on the conservation treatment of a 19th century Pietre Dure and micromosaic tabletop belonging to the Josiah Quincy house of Historic New England. The stone tabletop, positioned on top of a painting and gilded wooden base, had and been conserved in the past.\u00a0 Her treatment was readdressing this past treatment and returning it to exhibit-able condition.
\nPietre Dure translates into English as “hard stone”.\u00a0 The Pietre Dure portions consist of decorative stones set into the carved channels within the black marble base and adhered with a rosin and beeswax.\u00a0 The micromosaic areas are images made up from tiny tesserae called smalti.\u00a0 The smalti are cut to shape and inserted into an adhesive of linseed oil, lime and marble dust.\u00a0 The top surface was polished to a flat surface and the gaps between the tesserae were filled with tinted beeswax.\u00a0 This beeswax can be seen under ultraviolet light, but it has often been lost through over cleaning and use.
\nThe table top was in poor condition.\u00a0 The four sections were poorly adhered and slightly misaligned.\u00a0 A large crack in the stone tabletop ran across the middle of the tabletop and transected both the Pietre Dure and the micromosaic elements of the table.\u00a0 Two stone inlays were missing and there were losses in the micromosaic along the central break.
\nThe conservation treatment started with a surface cleaning of calcium saturated water with the pH raised to 8.5 with ammonia and added drops of Triton.\u00a0 Acetone was wicked into the old joins to dissolve the older restoration adhesive.\u00a0 B72 and microballons were used to glue the pieces back together.
\nFor the conservation of the Pietre Dure portions two options were considered.\u00a0 In Florence, the missing elements would have been replaced with new cut stone.\u00a0 The Pietre Dure objects are decorative and require a high level of finish.\u00a0 Another Italian treatment option is to cast crushed stone and resin to recreate the missing inlays.\u00a0 This second approach was chosen and the new Pietre Dure elements were created with tinted epoxy bulked with fumed silica cast into silicone rubber molds.\u00a0 In some areas it was necessary to back of the Pietre Dure areas of loss with a layer of Japanese tissue coated with B72. \u00a0The epoxy elements were then cast directly into the loss.\u00a0 Gamblin conservation colors were used to finish off the top of these fills and a layer of Acrysol WS24 was brushed\u00a0on top to give a polished shine.
\nThe micromosaic repairs were based on similar micromosaic designs.\u00a0 Since the micromosaics were mass produced with only a small range of designs, similar images could be used as guidelines for decorative elements on the fills.\u00a0 The areas of loss in the micromosaics were backed with acid free matt board topped with a layer of modostuc.\u00a0 Gamblin conservation colors were used to inpaint the surface in two steps.\u00a0 The first step painted the background colors and the second step painted the individual small tesserae.
\nThis was an elegant and well executed treatment with results that were aesthetically pleasing and reversible.\u00a0 Under close examination, the areas of filled loss are distinguishable from the original material.\u00a0 This was a great talk and I hope to get a chance to work on micromosaics someday!<\/p>\n","protected":false},"excerpt":{"rendered":"
Elizabeth La Duc gave an engrossing talk in the Objects Specialty session on the conservation treatment of a 19th century Pietre Dure and micromosaic tabletop belonging to the Josiah Quincy house of Historic New England. The stone tabletop, positioned on top of a painting and gilded wooden base, had and been conserved in the past.\u00a0 … Continue reading “44th Annual AIC meeting, May 17, 2016, "When in Rome, do as the Romans do? The Conservation of an Italian Marble and Micromosaic Tabletop\u201d by Elizabeth La Duc”<\/span><\/a><\/p>\n","protected":false},"author":123,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"footnotes":""},"categories":[2,32,16],"tags":[76],"class_list":["post-14453","post","type-post","status-publish","format-standard","hentry","category-annual-meeting","category-objects","category-specialty-sessions","tag-aics-44th-annual-meeting"],"_links":{"self":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/posts\/14453","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/users\/123"}],"replies":[{"embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/comments?post=14453"}],"version-history":[{"count":0,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/posts\/14453\/revisions"}],"wp:attachment":[{"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/media?parent=14453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/categories?post=14453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/resources.culturalheritage.org\/conservators-converse\/wp-json\/wp\/v2\/tags?post=14453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}