There's a bit of research happening here right now - not only for some work projects, but also for a little bit of extra. There was, you see, this project at the last Textile Forum to try and find out about how membrane threads were made.
Membrane threads are, to explain it very quickly, the cheap version of gold (or silver) threads. Instead of wrapping a strip of gold or gilt silver around a fibrous core, organic material is gilded or silvered with leaf metal and then cut into strips and wound around a core. Usually, that core is made of cheaper material as well, and not of silk like usual for the proper gold threads.
In our case, we used bovine gut membrane and linen thread as core, plus leaf silver for the silvering. There was a stack of questions when we started the project, and then there were more and more questions, and now there is still a lot, but also mostly new ones - which is nice, as it means we found answers for many of the questions from the first batch.
I will present our results in August at the EAA conference, and I'm already looking forward to that a lot. The next steps will be a comparison between the originals and our results (where one of the outcomes will, very obviously, be that ours are not very well crafted...) and then we will know more about how our process compares with the original one.
For now, though, I am very happy with what we did.
Even though we lack proficiency in all the relevant steps (mixing the appropriate glue, gilding the membrane, cutting it and winding it around the core), we have arrived at a workable solution for all the process steps that feels like it would be suitable for actual production. It's still a complex, time-consuming process, but then that's the case with so many texile-related tasks that it fits right in.
And I can't tell you how nice and satisfying it felt to actually produce silver thread in our last go at this reconstruction process!