If you're following me on Instagram, you may have seen some pictures of this on-going project already. It is, so to say, a left-over from last year's European Textile Forum, where we tried to explore the making of membrane gold threads.

Membrane gold threads are the cheaper version of real gold threads - it's a gilt animal membrane wrapped around a fibrous core. In our case, we built on the analysis results of some Italian threads that Cristina Scibé is researching.

There's a lot of unknowns or insecure things in the reconstruction of the process, and we were (and mostly still are) unfamiliar with most of the materials involved, so there was a really steep learning curve and there were plenty of "d'oh" moments.

But we have arrived at a process that is working, and that would be plausible also for production.

The photo shows the two spindles I am working with for wrapping strips of stuff around the core - one with the two linen single yarns, and the other with the wrapped yarns. These are not membrane strips, but modern metal and metallised plastic strips, done for practise purposes, as the membrane is a little too much work and too much of a resource to use as training material.

It's an utterly fascinating project... and I will give a little presentation about it on the EAA in Belfast this year. I'm already very excited about that!

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!

At last year's Textile Forum, one of our topics was exploring how membrane gold threads may have been made. That is, in theory, a simple process - you take bovine membrane, gild it with silver-gilt leaf metal, then wind it around a fibrous core consisting of two spun vegetable fibre threads.

Simple, right? Well. As was to be expected, it's of course not so simple. First of all, how is the leaf metal attached to the membrane? There are a number of possibilities to do so. We tried using both oil and gelatin glue, and both worked. None of us was very proficient at gilding, but well, it was good enough for our purposes. 

Next step: Cutting the silvered skin into strips. The original strips were less than one millimetre wide, and that caused problems as well - both with the cutting (which could be done with scissors, or with knives, we don't really know) and with the strips afterwards. Because it turned out that if you cut very thin strips, they start to curl up. Which is not very helpful for the following steps. There's also the question of how long the strips were... and there are no analyses that I know of which look at the length of the strips used to wind around cores. Or, in the case of flat strips, the length of these.

 We found it much, much easier to wind a very long strip around the core than to use shorter ones, as the start and end always caused us problems. So we tried glueing the individual strips together... which basically worked very well, but we had issues with the glue: it was too brittle once dried.

So one of our next steps will be to try a different glue. There's also the possibility to modify animal glues with different additives to change their properties, including their elasticity, but we lack recipes for that, so we'll probably go with just the pure glues for now. (If you happen to know of any good, reliable recipes for making parchment glue or modifying it... they'd be very welcome!)

Things like that are the main reason why it's so important to do tests, and experiments, and try to recreate or reconstruct the actual working processes. Even if you're the best of researchers, it's just impossible to find out about all these small pitfalls by reconstructing a process on paper only. I'd never have considered how important the right choice of glue might be, or that the glue might be a crucial factor in how the membrane behaves - even though I've worked with glues a lot through my hobby bookbinding, and know from there that things will happen if you use the wrong glues, or too much or too little of them, or cover something on one side only. Which means I should have known, and as soon as the problem popped up, I went "oh yes, of course, that's an influence factor" - but before that... well. There's just too many things going on in any complex process (and most craft processes are complex processes) to consider them all without having the actual feedback from actual things being done.

And that all said, I will return to my preparation of some more tests in the project. It's guaranteed we will find some more questions, but I am hoping that we will find a few more answers too!

My blog thingie is, it seems, trying to make me look like a bit of a fool - I used one of the post drafts that had not gotten through, but the progamme then obligingly posted it under a different date. Very nice of you, blog thingie, thank you so much. Not.

On to nicer things than wayward software, though! There is a large Experimental Archaeology Conference coming up, running May 1-3. It's in Torun in Poland, but will be a hybrid event, so if you'd like to join in on short notice, you can.

13The full programme is here: https://exarc.net/meetings/eac13 and there is a session with focus on textiles on Monday, May 1, starting at 14:30 (Session 3.B).

You can follow the presentations online via https://www.youtube.com/@exarc. Links will also be included in the website. For extra chats and discussion there's a Discord server you can join. For more information on the conference, go here: https://exarc.net/meetings/eac13/how-attend.

So I hope there's something interesting on the programme for you, and that you will have fun participating!