Good evening, MuseumLers – If the sweater is made from wool fibre, please do not use Orvus (sodium lauryl sulfate, an anionic detergent). Further research in the field has determined that anionic detergents bond with protein fibres and are very difficult to rinse completely from the fibre. Nonionic detergents should be used for cleaning protein fibres like wool and silk. I suggest a careful vacuuming inside and out with vacuum cleaner (HEPA filter one if you are doing the vacuuming inside the museum) first. If you want to go further than that, you definitely need to first check the water fastness of all of the coloured components (not just the blue coloured one). You should test the fastness using the solution you want to use. Warm deionized water with no added detergent is an extremely good cleaning solution all by itself. Plus no additional rinsing is needed to rinse out any detergent used. Deionized water can be bought in gallon and 2.5 gallon containers at most grocery or drug stores (do read the label carefully). Remember that the sweater will be incredibly heavy when completely wet out and must be kept flat and fully supported. Please feel free to contact me off-line if you need further clarification or have additional questions. Regards, Meg . _ _ _ _ _ _ _ _ _ ___________ Margaret E. Geiss-Mooney Textile/Costume Conservator & Collections Management Consultant Professional Associate - AIC 707-763-8694 [log in to unmask] …spot check with cold water and a q-tip first, then the same with a wee bit of Orvus. Another thing you might try is vacuuming through a screen. … …navy-blue wool letter sweater that feels like it’s full of gritty dirt. My first impulse it to wash it (hand wash in cold water and Orvus paste), but I’m a little concerned that the blue might run and stain the gold edging on the letter. The sweater is well used, but may have only been dry-cleaned before we got it. Any advice? … ========================================================= Important Subscriber Information: The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes). If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).