Email digest for the Global Conservation Forum (ConsDistList) egroup. ------------------------------------------------------------------------------------------------------------
1. RE: Canvas Stamp 2. RE: XRF on ethnographic collection 3. x2 Career opportunities - Organic materials studio, British Museum, 4. RE: XRF on ethnographic collection 5. RE: Canvas Stamp 6. RE: Canvas Stamp 7. RE: Calcium deposit on bronze sculptures in fountains ------------------------------------------------------------------------------------------------------------ 1.From: Christian Mueller-Straten Posted: Wednesday November 12, 2025 7:03 AM Subject: RE: Canvas Stamp Message: Hi Heather, taken together all information provided by you and contributors, it fits exactly to this: "Appendix 1: Frame marks Canvas for artists was subject to taxation until 1831 (see British portrait painters and their canvas sizes, 1625-1850, section 1.2, on this website). For further information, see Sally Woodcock, 'Excise stamps on artists' canvases: lost threads and loose ends', in A. Wallert (ed.), Painting Techniques, History, Materials and Studio Practice, Amsterdam: Rijksmuseum, 2016, pp.192–7. Three marks, each with a different purpose, can often be found on artists' canvas: The supplier's mark gives their name, address and type of material. [here apparently missing- CMS] The frame mark consists of a compartmentalized frame with changeable numbers and letters; these record the dimensions of the material and certain other information such as the year. The duty stamp took the form of a crown above a royal cipher, GR, interlaced and reversed, often with the word 'LINENS' below; it indicated that duty had been charged on the canvas recorded in the frame mark." Best Christian ------------------------------ [Christian] [Mueller-Straten] [Researcher, Publisher, Art Historian] [Owner] [Verlag Dr. Christian Mueller-Straten] [Munich] [Germany] [0049-89-839 690 43] [https://www.museum-aktuell.de] https://www.museum-aktuell.de/CEO ------------------------------ ------------------------------------------- Original Message: Sent: 11-10-2025 01:23 From: Mohammed Rampurawala Subject: Canvas Stamp Hi Heather, Advance AI search gave me this result, although I was unable to find any details on the internet that could support this result. I am afraid that AI misinterpreted the characters in the image, but I wonder where did it find the details about the canvas supplier mentioned in the answer :-) can you please identify the stamp in this image?? Based on the visible letters and the style of the marking, the image shows a supplier's stamp from A. J. Vibert, a well-known 19th-century purveyor of artist's materials in Paris. # Stamp Identification The stamp on the canvas can be identified as belonging to A. J. Vibert. These marks, known as "cachets de marchand de couleurs" (colormen's stamps), were applied to the back of prepared canvases sold to artists. ## Details of the Vibert Stamp Visible Text: Although faint, the key features of a Vibert stamp are visible: The initials "A. J." are often present.The name "VIBERT" is the most prominent part of the mark.The location "A PARIS" was commonly included.A large letter, in this case, a "B", may indicate the quality or type of the canvas. Historical Context: Supplier: Jean-Pierre Vibert (and later his successors) operated in Paris during a crucial period for artists, including the Impressionists.Purpose: These stamps are valuable for art historians and conservators as they help to date and authenticate paintings from that era. Finding a Vibert stamp on the back of a painting provides a clue about its origin and timeframe. Material: The fabric appears to be linen canvas, which was a common support for oil paintings and the primary material sold by suppliers like Vibert. ------------------------------ Mohammed Rampurawala Paper Conservator Al Jamea Tus Saifiyah Surat India ------------------------------ Original Message: Sent: 11-07-2025 15:31 From: Heather Galloway Subject: Canvas Stamp 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 ------------------------------ 2.From: Lidwien Speleers Posted: Wednesday November 12, 2025 7:03 AM Subject: RE: XRF on ethnographic collection Message: Dear Stefanie, I cannot help you further with this. But I can say that doctors point X-ray beams on living humans. And even my dentist does it to check if my teeth have holes in them. So pointing an X-ray beam on a human being is not inacceptable as such. Kind regards, Lidwien Speleers Paintings conservator Dordrecht Netherlands ------------------------------------------- Original Message: Sent: 11/10/2025 6:39:00 AM From: Stefanie Scheerer Subject: XRF on ethnographic collection I am facing the following situation: An ethnographic museum in Germany is planning to perform pesticide measurements on their entire collection, formerly collected across all continents. Included are also some sacred objects / objects for ritual purpose and potentially ancestors. However, so far there is no contact with the communities of origin. Nevertheless, the museum intends to measure every object with XRF. ( I am aware of the limits of XRF on organic pesticides) I brought to the museum's attention that source communities should be generally contacted and asked for permission before performing XRF analyses. In the case of this forthcoming project there is only little time left for further actions. Instead, occupational health and safety issues require testing to be performed within the next few months. Indirect wipe sampling is most likely not an option, since XRF may not sensitive enough to give reliable results. However, any ideas on indirect XRF testing of wipes/swabs are also appreciated. Other indirect analytical methods such as GC/MS are too expensive to be performed on the entire collection. Currently, I'm wondering how other museums address this problem. Are you aware of any museum that has a protocol when collection-wide XRF analyses is planned? It would be very helpful to see any written document addressing this issue. Are you aware of other museums performing or not performing XRF analyses on sacred objects / ancestors / objects for ritual purposes when contact to source communities does not exist? Should ancestral items be treated like human remains or possibly like human beings. This would, however, mean that XRF analysis must not be performed, since pointing an X-ray beam at a human being is inacceptable. Do you maybe know whom I could contact for such information? Thank you very much for your support and taking your time on this! Sincerely, Stefanie Dr. Stefanie Scheerer Microbiology & Conservation Stuttgart, Germany [email protected] ------------------------------ Stefanie Scheerer Microbiologist & Conservator Freelance/Private Practice/Self-employed/Independent Stuttgart Germany ------------------------------ 3.From: Alex Owen Posted: Wednesday November 12, 2025 7:04 AM Subject: x2 Career opportunities - Organic materials studio, British Museum, Message: We have two positions open in the organic materials studio at the British Museum. One permanent, which will focus on the conservation of wood, furniture and decorative surfaces. The other is fixed-term, focusing on the conservation of archaeological materials and decorative surfaces. However both candidates should be able to work across a range of organic materials. Conservator: Organics Full-time, On-site Permanent x1, Fixed-Term x1 (until November 2026) £33,470 per annum Application deadline: 12pm (midday) on Monday, 1 December 2025 About the role This is a fantastic opportunity for an early or early-to-mid career organics conservation specialist to join our friendly and dynamic team of conservation professionals at the British Museum. The successful candidate will have the opportunity to engage in lots of practical work with the collection and to collaborate with stakeholders across the Museum as well as communities across the country and world. You will help to care for the British Museums collections through a combination of interventive and preventive measures, bringing your specialist knowledge in the conservation of a range of organic materials. In 2024, the British Museum received 6.5 million visitors, more than any other museum in the UK. Against this backdrop, the Museum is now undergoing an extraordinary transformation, both intellectual and physical, including the loan of the Bayeux tapestry <https://www.britishmuseum.org/about-us/press/press-releases/bayeux-tapestry-displayed-british-museum> on which the team will work closely. For more details, and to apply, please follow this link: https://bmrecruit.ciphr-irecruit.com//templates/CIPHR/jobdetail_8477.aspx ------------------------------ Alex Owen Senior Conservator: Organic Objects The British Museum London United Kingdom ------------------------------ 4.From: Luis de Almeida Nieto Posted: Wednesday November 12, 2025 7:05 AM Subject: RE: XRF on ethnographic collection Message: Hello Dr. Scheerer, This is a very interesting situation that I, as an X-ray researcher, had not encountered or considered. I am not well-versed enough with the ethical/spiritual aspects of the problem to provide any useful insight on that, but I can comment on the use of X-rays for analysis on living human beings. Pointing an X-ray beam at a living human being is a fairly common practice in medicine, so shouldn't be considered unacceptable, as you state in your post. It certainly is not something that should be done inconsiderately and must always require informed consent, but shouldn't be outright disregarded as an option in case it is decided that the objects should be considered as human beings. >From an object safety point of view, XRF analysis, if conducted correctly, is >generally considered a safe analytical technique for most objects, as the >radiation exposure is fairly low and unlikely to cause permanent physical >changes to the object. So if there is concern (by part of the communities of >origin or the conservators) on the safety of the object, I would argue that >XRF would be comparable to other non-invasive analytical methods, like UV or >visible light photography. I would not want my comments to be misunderstood as an argument for disregarding the important ethical questions you pose and I am very grateful that you brought this topic to the attention of the community. Best regards, Luís M. de Almeida N. Conservation Scientist Delft, The Netherlands ------------------------------ Luis de Almeida Nieto PhD Student TU Delft Department of Materials Science and Engineering Delft Netherlands ------------------------------ ------------------------------------------- Original Message: Sent: 11-10-2025 06:38 From: Stefanie Scheerer Subject: XRF on ethnographic collection I am facing the following situation: An ethnographic museum in Germany is planning to perform pesticide measurements on their entire collection, formerly collected across all continents. Included are also some sacred objects / objects for ritual purpose and potentially ancestors. However, so far there is no contact with the communities of origin. Nevertheless, the museum intends to measure every object with XRF. ( I am aware of the limits of XRF on organic pesticides) I brought to the museum's attention that source communities should be generally contacted and asked for permission before performing XRF analyses. In the case of this forthcoming project there is only little time left for further actions. Instead, occupational health and safety issues require testing to be performed within the next few months. Indirect wipe sampling is most likely not an option, since XRF may not sensitive enough to give reliable results. However, any ideas on indirect XRF testing of wipes/swabs are also appreciated. Other indirect analytical methods such as GC/MS are too expensive to be performed on the entire collection. Currently, I'm wondering how other museums address this problem. Are you aware of any museum that has a protocol when collection-wide XRF analyses is planned? It would be very helpful to see any written document addressing this issue. Are you aware of other museums performing or not performing XRF analyses on sacred objects / ancestors / objects for ritual purposes when contact to source communities does not exist? Should ancestral items be treated like human remains or possibly like human beings. This would, however, mean that XRF analysis must not be performed, since pointing an X-ray beam at a human being is inacceptable. Do you maybe know whom I could contact for such information? Thank you very much for your support and taking your time on this! Sincerely, Stefanie Dr. Stefanie Scheerer Microbiology & Conservation Stuttgart, Germany [email protected] <[email protected]> ------------------------------ Stefanie Scheerer Microbiologist & Conservator Freelance/Private Practice/Self-employed/Independent Stuttgart Germany ------------------------------ 5.From: Heather Galloway Posted: Wednesday November 12, 2025 1:52 PM Subject: RE: Canvas Stamp Message: Thank you for the summary Christian. Thanks too to Brian for Cathey Proudlove's name! Jacob Simon's name was offered up many times but it appears that it was based on her work which is credited in the database pdfs. She does have an article in the Restorer. I am working on site at the moment but when I get back to my home base libraries I hope to follow up with some of the articles. Thanks too for those who gave AI a shot. I appreciate Mohammad reminding us that AI can get things wrong! Best, Heather ------------------------------ Heather Galloway Conservator, Fellow Galloway Art Conservation 1305 W 80th St. Suite #225 Cleveland, OH 44102 ------------------------------ ------------------------------------------- Original Message: Sent: 11-12-2025 00:35 From: Christian Mueller-Straten Subject: Canvas Stamp Hi Heather, taken together all information provided by you and contributors, it fits exactly to this: "Appendix 1: Frame marks Canvas for artists was subject to taxation until 1831 (see British portrait painters and their canvas sizes, 1625-1850, section 1.2, on this website). For further information, see Sally Woodcock, 'Excise stamps on artists' canvases: lost threads and loose ends', in A. Wallert (ed.), Painting Techniques, History, Materials and Studio Practice, Amsterdam: Rijksmuseum, 2016, pp.192–7. Three marks, each with a different purpose, can often be found on artists' canvas: The supplier's mark gives their name, address and type of material. [here apparently missing- CMS] The frame mark consists of a compartmentalized frame with changeable numbers and letters; these record the dimensions of the material and certain other information such as the year. The duty stamp took the form of a crown above a royal cipher, GR, interlaced and reversed, often with the word 'LINENS' below; it indicated that duty had been charged on the canvas recorded in the frame mark." Best Christian ------------------------------ [Christian] [Mueller-Straten] [Researcher, Publisher, Art Historian] [Owner] [Verlag Dr. Christian Mueller-Straten] [Munich] [Germany] [0049-89-839 690 43] [https://www.museum-aktuell.de] https://www.museum-aktuell.de/CEO <https://www.museum-aktuell.de/CEO> ------------------------------ Original Message: Sent: 11-10-2025 01:23 From: Mohammed Rampurawala Subject: Canvas Stamp Hi Heather, Advance AI search gave me this result, although I was unable to find any details on the internet that could support this result. I am afraid that AI misinterpreted the characters in the image, but I wonder where did it find the details about the canvas supplier mentioned in the answer :-) can you please identify the stamp in this image?? Based on the visible letters and the style of the marking, the image shows a supplier's stamp from A. J. Vibert, a well-known 19th-century purveyor of artist's materials in Paris. # Stamp Identification The stamp on the canvas can be identified as belonging to A. J. Vibert. These marks, known as "cachets de marchand de couleurs" (colormen's stamps), were applied to the back of prepared canvases sold to artists. ## Details of the Vibert Stamp Visible Text: Although faint, the key features of a Vibert stamp are visible: The initials "A. J." are often present.The name "VIBERT" is the most prominent part of the mark.The location "A PARIS" was commonly included.A large letter, in this case, a "B", may indicate the quality or type of the canvas. Historical Context: Supplier: Jean-Pierre Vibert (and later his successors) operated in Paris during a crucial period for artists, including the Impressionists.Purpose: These stamps are valuable for art historians and conservators as they help to date and authenticate paintings from that era. Finding a Vibert stamp on the back of a painting provides a clue about its origin and timeframe. Material: The fabric appears to be linen canvas, which was a common support for oil paintings and the primary material sold by suppliers like Vibert. ------------------------------ Mohammed Rampurawala Paper Conservator Al Jamea Tus Saifiyah Surat India Original Message: Sent: 11-07-2025 15:31 From: Heather Galloway Subject: Canvas Stamp 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 ------------------------------ 6.From: Steven Prins Posted: Wednesday November 12, 2025 1:53 PM Subject: RE: Canvas Stamp Message: Hi Heather, I cannot claim to recognize the stamp. But I have often been able to enhance their legibility with UV and/or IR imaging. I use an old Sony F-818 for the IR. Much more sophisticate equipment is now available for IR imaging. I imagine broader multispectral imaging now more widely available would also be helpful. Second suggestion would be image stacking. Combine the preserved portions from the different impressions and see what you get. There's a lot you can do with Photoshop, or similar. Your query also begs a question that has ben bugging me for years now, Does anyone know what has become of Alex Katlan? His site is still up and running but he seems to have withdrawn from communication. He was always so helpful with such questions and such a pleasure to talk to. Good luck with your quest. Best wishes to all, Steven ------------------------------ Steven Prins Santa Fe, NM ------------------------------ ------------------------------------------- Original Message: Sent: 11-07-2025 15:31 From: Heather Galloway Subject: Canvas Stamp 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 ------------------------------ 7.From: Myriam Lavoie Posted: Wednesday November 12, 2025 7:25 PM Subject: RE: Calcium deposit on bronze sculptures in fountains Message: @Sasha Drosdick <https://www.culturalheritage.org/profile?UserKey=96081e44-4e76-4265-84c0-b470d24a645a>, could you write to me directly at [email protected] ? We can discuss your questions. Thanks! ------------------------------ 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 ------------------------------ 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.
