Email digest for the Global Conservation Forum (ConsDistList) egroup. ------------------------------------------------------------------------------------------------------------
1. RE: Need help identifying water damage on paper 2. RE: Query: Dense Black Patinas Incorporating Carbon Pigments 3. Zoom Lecture: London's Lost Victorian and Edwardian Interiors, 20 November 2025 4. RE: Calcium deposit on bronze sculptures in fountains 5. RE: Query: Dense Black Patinas Incorporating Carbon Pigments 6. Canvas Stamp ------------------------------------------------------------------------------------------------------------ 1.From: Prue McKay Posted: Friday November 7, 2025 7:23 AM Subject: RE: Need help identifying water damage on paper Message: I would say that you have a combination of things happening but your main problem is mould. The ink doesn't seem to have suffered in terms of dissolution or movement. Mould has digested the paper in places, so the paper has disappeared. In other places the mould is visible and has stained the paper. The dark lines might also be tidelines, moving paper degradation products to the edges of where the water got to, where they can concentrate and become darker over time. In my institution we simply brush vacuum mouldy items, then digitise them (all in an isolated facility for this purpose). Access to the originals is strictly controlled and clients must only access the digital copy. ------------------------------ Prue McKay Senior Conservator National Archives of Australia ------------------------------ ------------------------------------------- Original Message: Sent: 11-03-2025 04:09 From: Jetawat Sawadmanaschai Subject: Need help identifying water damage on paper Hello colleagues, As I'm not specializing in the field of paper conservation, I need the community's help once more for something I'm currently unsure about. While examining a book with visible water damage, I noticed some marks on the pages that I can't confidently identify. I'm not sure whether they are mould stains, water staining, or perhaps ink that has dissolved due to water expose. I've attached some images for reference and would greatly appreciate any insights or guidance on how to tell the difference between these causes. Thank you again for your help and expertise! ------------------------------ Jetawat Sawadmanaschai Archaeologist / Conservator Reform Archaeology Co., Ltd. Bangkok Thailand UCL Institute of Archaeology (Alumni) MA Principle of Conservation London United Kingdom ------------------------------ 2.From: Daniel Ravizza Posted: Friday November 7, 2025 8:35 AM Subject: RE: Query: Dense Black Patinas Incorporating Carbon Pigments Message: Hi Caitlin, I have used this very same patina for a conservation treatment of Continuum by Charles O Perry, a bronze which in on the Mall in Washington DC. I did this a few years ago when I was on staff at the Smithsonian National Air and Space Museum. It works well and creates a dense hard, opaque surface that looks much like flat black spray paint. Please let me know if I can help or if you would like more details on how to use and apply it. Best, Daniel ------------------------------ Daniel Ravizza Williamsport, PA United States [email protected] ------------------------------ ------------------------------------------- Original Message: Sent: 11-06-2025 14:27 From: Robert Price Subject: Query: Dense Black Patinas Incorporating Carbon Pigments Dear Caitlin, Thank you for pointing out Joanna Rowntree's 2002 OSG abstract - what a shame there isn't more. Generally, torch applied black patinas produced with cupric nitrate and black pigment are quite stable, especially if waxed properly and maintained. Andrew Baxter and Steve Roy, who just taught at the Getty's second Bronze Patination for Conservators Workshop, regularly apply this patina and can speak more authoritatively about its longevity based on their decades of experience. In terms of patinas "popping off", as Rowntree describes, densely applied patinas can potentially spall or flake off but this is usually connected to application technique rather than the chemicals or pigments used. As for the issue with cupric nitrate patinas on silicon bronze resulting in the formation of cuprite, which has been described in Patrick Kipper's Patinas for Silicon Bronze, this does not always occur and appears to be somewhat dependent on environmental factors. Lots to discuss here, so please feel free to email or call me directly. ------------------------------ Robert Price Associate Conservator J. Paul Getty Museum Los Angeles United States [email protected] <[email protected]> ------------------------------ Original Message: Sent: 11-05-2025 16:39 From: Caitlin Gallupe Subject: Query: Dense Black Patinas Incorporating Carbon Pigments Dear Conservators, I'm a recent Objects conservation graduate working with a private conservator, and I've encountered a bronze sculpture featuring a dark, dense surface patina composed of a mixture of cupric nitrate and a carbon-based pigment. I'm hoping to locate more information on this patination technique and I'd be very grateful for any articles, case studies, experiential anecdotes, or references to related research on pigmented patinas and their issues/aging. So far, the only reference we've been able to locate is an intriguing abstract by the late Joanna Rowntree "Issues of contemporary patination on outdoor bronze sculpture" from AIC 2002 Objects Specialty Group Postprints, which mentions similar black patinas that incorporate carbon-based pigments. Thank you for any resources you can share, Caitlin Gallupe Victoria BC Canada [email protected] <[email protected]> 3.From: Lisa Oestreicher Posted: Friday November 7, 2025 12:49 PM Subject: Zoom Lecture: London's Lost Victorian and Edwardian Interiors, 20 November 2025 Message: Hello I would like to publicise a Zoom lecture which will be held on 20 November 2025. The information is as follows: The Historic Interiors Group of the Institute of Conservation presents a Zoom lecture: London's Lost Victorian and Edwardian Interiors How interior design influenced and reflected the social and cultural life of high society in London. London has always had the best, most fashionable and expensive of everything, and in the 18th, 19th and early 20th centuries interior design played a major part in the capital's social and cultural life. Houses were conceived as stages and settings for grand entertaining and private life, as settings for works of art, and as vehicles for self-expression by their owners. Many of them accordingly had their homes photographed, especially by Bedford Lemere & Company, whose archive is now held by Historic England. Steven Brindle's lecture, covering the years 1880-1914, is based on the first half of his book London - Lost Interiors (Atlantic Publishing, 2024). Steven presents a varied array of images of domestic interiors in London, most of which are 'lost' in one way or another. The photographs are what survives - and the interiors which were photographed represent a small fraction of what once existed. They testify to the fact that interior design is a major art form, but that it is a fragile and fugitive one. Zoom lecture 6.30pm – 8pm GMT 20 November 2025 £10 non-members, Free to ICON members. If you have any queries regarding the above please do not hesitate to contact me. Best wishes Lisa Lisa Oestreicher Architectural Paint Research Tel. 01225 466 374 <tel:01225 466 374> Mobile 07809 014939 <tel:07809 014939> www.historicpaint.com <http://www.historicpaint.com/> 4.From: Myriam Lavoie Posted: Friday November 7, 2025 12:49 PM Subject: RE: Calcium deposit on bronze sculptures in fountains Message: Hello again! @Craig Deller <https://www.culturalheritage.org/people/craig-deller1>, thank you for the information provided. Your experience is quite telling. The results we had for the fountain water is 91 mg/L (ppm), which is 'moderately hard' according to your chart, which seems a helpful comparision. Thankfully, the fountain has a modern automated system and the city is open to add a filtering component - we just need to figure what system exactly. At first read, a lot of softening systems swap calcium / potassium ions for sodium ions, which does not seem like a big win with bronzes. But we will shortly have a discussion with the company who does the fountain water system maintenance, and we will see if they can offer that filters calcium without adding sodium or other problematic ions. @Martha Singer <https://www.culturalheritage.org/people/martha-singer>, bonjour très chère, merci pour le tuyau. J'espère que tu vas bien. Si tu as envie de venir pratiquer ton français et manger des bons croissants, tu es toujours la bienvenue à Québec. Bises. @Tom Podnar <https://www.culturalheritage.org/profile?UserKey=b04e06e7-8ef9-41c8-9b53-90f7f5d868ee>, thanks for the invitation, I will reach out shortly. ------------------------------ Myriam Lavoie Sculpture Conservator Centre de Conservation du Quebec Quebec Canada ------------------------------ ------------------------------------------- Original Message: Sent: 11-04-2025 11:44 From: Myriam Lavoie Subject: Calcium deposit on bronze sculptures in fountains Good day, I am looking for information pertaining to acceptable calcium levels in water in a fountain and how to possibly reduce it. A local museum has a fountain with several bronze sculptures (the fountain part is under the care of the city). Most of the sculptures are above water so only get splashed, but a few get more water on their surface. They develop a calcium / salt deposit, fast enough that it needs to be removed yearly. Despite waxing the bronze sculptures regularly, the salt crust + yearly cleaning ends up damaging the patina in some areas, which is problematic. The city had the water tested, and the calcium level are considered 'normal' for pools and others artificial water features, but I couldn't find pertinent informations on what could be acceptable in this setting, to not affect the bronze. Otherwise the water quality is quite good, with a neutral pH and no chlorine. They are open to make adjustment to the water system with guidance. I was wondering if anyone has had a similar situation and done reasearch on what systems are beneficial to remove calcium salts, without introducing other problematic ions, or if anyone has papers or other references to offer on the subject. Thanks in advance, as always. ------------------------------ Myriam Lavoie Sculpture Conservator Centre de Conservation du Quebec Quebec Canada ------------------------------ 5.From: Caitlin Gallupe Posted: Friday November 7, 2025 2:11 PM Subject: RE: Query: Dense Black Patinas Incorporating Carbon Pigments Message: Thank you all so much for your input! It has been very helpful to hear your thoughts while figuring out our main condition issue of flecks popping off leaving bare copper exposed- as it relates to the patina itself, application technique, environmental factors or a delightful mix of all three. I will respond to you separately soon off the thread, but thanks again for your thoughts and suggestions. Caitlin GallupeVictoria BC [email protected] <[email protected]> ------------------------------------------- Original Message: Sent: 11/7/2025 8:06:00 AM From: Daniel Ravizza Subject: RE: Query: Dense Black Patinas Incorporating Carbon Pigments Hi Caitlin, I have used this very same patina for a conservation treatment of Continuum by Charles O Perry, a bronze which in on the Mall in Washington DC. I did this a few years ago when I was on staff at the Smithsonian National Air and Space Museum. It works well and creates a dense hard, opaque surface that looks much like flat black spray paint. Please let me know if I can help or if you would like more details on how to use and apply it. Best, Daniel ------------------------------ Daniel Ravizza Williamsport, PA United States [email protected] ------------------------------ ------------------------------------------- Original Message: Sent: 11-06-2025 14:27 From: Robert Price Subject: Query: Dense Black Patinas Incorporating Carbon Pigments Dear Caitlin, Thank you for pointing out Joanna Rowntree's 2002 OSG abstract - what a shame there isn't more. Generally, torch applied black patinas produced with cupric nitrate and black pigment are quite stable, especially if waxed properly and maintained. Andrew Baxter and Steve Roy, who just taught at the Getty's second Bronze Patination for Conservators Workshop, regularly apply this patina and can speak more authoritatively about its longevity based on their decades of experience. In terms of patinas "popping off", as Rowntree describes, densely applied patinas can potentially spall or flake off but this is usually connected to application technique rather than the chemicals or pigments used. As for the issue with cupric nitrate patinas on silicon bronze resulting in the formation of cuprite, which has been described in Patrick Kipper's Patinas for Silicon Bronze, this does not always occur and appears to be somewhat dependent on environmental factors. Lots to discuss here, so please feel free to email or call me directly. ------------------------------ Robert Price Associate Conservator J. Paul Getty Museum Los Angeles United States [email protected] <[email protected]> ------------------------------ Original Message: Sent: 11-05-2025 16:39 From: Caitlin Gallupe Subject: Query: Dense Black Patinas Incorporating Carbon Pigments Dear Conservators, I'm a recent Objects conservation graduate working with a private conservator, and I've encountered a bronze sculpture featuring a dark, dense surface patina composed of a mixture of cupric nitrate and a carbon-based pigment. I'm hoping to locate more information on this patination technique and I'd be very grateful for any articles, case studies, experiential anecdotes, or references to related research on pigmented patinas and their issues/aging. So far, the only reference we've been able to locate is an intriguing abstract by the late Joanna Rowntree "Issues of contemporary patination on outdoor bronze sculpture" from AIC 2002 Objects Specialty Group Postprints, which mentions similar black patinas that incorporate carbon-based pigments. Thank you for any resources you can share, Caitlin Gallupe Victoria BC Canada [email protected] <[email protected]> 6.From: Heather Galloway Posted: Friday November 7, 2025 9:34 PM Subject: Canvas Stamp Message: I have an unlined British painting in my studio from 1822 that has a repeated canvas stamp that is difficult to read. The artist worked in London. The stamp is topped with a crown and the bottom appears to read "2J8" but most of the image did not take well to the linen. I'm attaching an image of the clearest impression in the hopes that someone might recognize it. Thanks, Heather ------------------------------ Heather Galloway Conservator, Fellow Galloway Art Conservation 1305 W 80th St. Suite #225 Cleveland, OH 44102 ------------------------------ You are subscribed to "Global Conservation Forum (ConsDistList)" as [email protected]. To change your subscriptions, go to http://community.culturalheritage.org/preferences?section=Subscriptions. To unsubscribe from this community discussion, go to https://community.culturalheritage.org/HigherLogic/eGroups/Unsubscribe.aspx?UserKey=d16eaa87-0f69-494b-9f2f-303dbc1222e1&sKey=fab9aa4f27a04c5d876e&GroupKey=757a8f16-505f-4323-8e74-e376757aa9f7.
