A few weeks ago Carolyn left a note in the forum about her silver lace thread tarnishing. I sent Tricia a note about it, and then Carolyn and Tricia corresponded. Tricia sent me a copy, thinking the subject and her answer would be of interest. Has anyone else had such a serious tarnishing problem with this thread or another?
I believe that the wooden box Carolyn mentions storing her lace threads in is a divided carrier from Orleans Carpenters. If you have one or are getting one of the Embroiderers’ Story ones, think about not storing silver threads in it.
The silver thread for the lace sample is what tarnished. When I finished the sample piece I left the thread on the bobbins, with the clips on and the loose ends hanging off. The bobbins were left in an open wooden box, so they were exposed to room light, etc. Last week I got them out to set up a new piece with the leftover thread and saw that all the thread that was exposed, loose or on the top layer of the wound area not under the clip, had tarnished to a dark gray with rainbow accents – looks somewhat like those iridescent
metallics. Because the core is white it really showed up like candy stripe – my thread has many sections that does not have very tight coverage by the silver so lots of white shows through. Those sections were also much more stiff/brittle than the untarnished
I was inquiring on the forum because I wasn’t sure if the tarnish was part of the design plan, to be more authentic looking. I’ve held off on starting my new piece because it was going to be edging for a sachet, and would be exposed, so I am debating if I want the
tarnished look or not. I may modify plans to make something that would go under glass for better protection – but then I lose the glittery effect of the gold thread and moving parts with the oes.
Do you have advice on the best way to prevent the oxidation? Is it mostly light, moisture, or oxygen that causes it?
Sulfur is the main agent that tarnishes silver and the concentration of sulfur accelerates the tarnishing. There are different % of sulfur in different media – from the air (light) to skin and skin oils (higher) to certain woods and wood by-products (paper) which can be
pretty high. Some plastics will have sulfur concentrations depending on the plastic. The goals is to reduce the exposure to high sulfur contact to prolong the tarnish process, which will happen.
We choose the highest silver content (90%) thread as it will last the longest under good conditions. I will say that I have a spool of this thread that I bought in 2002 and it is still bright except for a light, light tarnish on the little bit peeking out from under the acid-free tissue it is wrapped with. I have other silver threads under glass that are now tarnished but took about 10-15 years to get that way. They are now 25 yrs old but not fully black – more brown.
My first guess is that the wooden box is the culprit here. When you got the kit, we had it wrapped on acid-free board with acid-free tissue around it to put it in the best conditions possible for storage. I am sorry that I hadn’t written a blog or something in the directions about storage of the silver. We debated about silver or false silver for the project. The GST is done in gold wire and not silver strip like the original jacket partly for that reason.
Mark, as a metals person, pointed out to us that the culture at the time would have understood that the silver would go black over time and would have accepted it as part of the process because they didn’t have any other option. Their value system relating to the materials would have accepted that. The big question comes, how fast did it happen on those beautiful pieces! Therefore we decided to work with original materials. We have options today and so fret about it.
I have been trying to track down a certain journal article written about a simple set of lab tests that can be done on paper products to ascertain the relative sulfur content. It was written to give museum curators a scale of test results to use to test display and storage
materials for silver and silver plate pots, etc. Everytime they are polished, a layer of silver is removed. So some materials are ok for short term display but not for long term storage. I need to try a few more libraries to get it – maybe the MFA library next. I am not sure how difficult the tests are for the home embroiderer to test her storage, pricking paper, etc.
I hope this explains things. I am so sorry that a layer of the silver has tarnished. I would suggest that you take a tarnish felt and wipe the surface and see if that removes it. I was able to remove a layer easily off my jewelry the other day with one.