When you're working with colours, definitions or descriptions of them are always an issue. Green as grass, blue as the sky, dark as the night - even these descriptions, time-honoured and always nice, include a large variety of shades.

It would be nice to have a good, solid way of describing colours, wouldn't it? Well. There's electronic colour checkers, there's colour space charts, and then... there's human beings.

One of the little side shenanigans we did at the Forum was test how well a colour checker fan works. These are printed colours with a defined number according to a system - you might be familiar with the RGB system, or have heard of CMYK. There's a number of other systems as well, but in this case, that's only relevant insofar as the number you'll write down as your colour name will change.

We asked people to sit down and try to describe the colours of some of our madder sample dyeings with help of the fan. (Thank you to everyone who did!) Everyone who I asked about how it went agreed on it being difficult, as the printed colour patches were not really matching the actual textile colours.

Well. Having had quite the experience with how dissimilar measurements done on the spinning angle were if taken by different persons, I was a bit suspicious from the start on how well the colour fan might work (or not). It would be really, really nice if it did, making the description of colours easier, and more reliable, and hope springs eternal. 

This is what we had as one set of samples:

It's a rather bad picture, but hopefully you can see that there's a little difference between some of the samples. Make up your own mind on how many groups you'd see regarding darkness/colour depth - myself, I see three in the originals and four in this (bad) picture, with the one to four pieces in the group having no discernable difference.

Here's the clincher: The cloth patches were not sorted by darkness when participants were doing the colour checking and matching. And... as a result, we had the same colour number assigned to the darkest shade and the lightest shade by different people.

Which, to me, means that this simple method is, unfortunately, out - and that you should not trust the colour numbers given by "comparison-by-eye" using a colour fan tool. 

Sigh. It would have been so nice, wouldn't it?

I'm back from the Forum and my recuperation afterwards - much needed, and much appreciated, and now it's tackling all the emails that have accumulated, and sending out all the orders that came in, and then... back to normal work plus the Forum homework.

And oh, there's homework. We ran a total of four experiments and one dyeing test during the week (yes, madness indeed). One was the continuation of Micky Schoelzke's exploration of fake purple that she started last year (you can read about that on the Forum homepage). Then I had the splendid idea of trying out mordanting with horsetail (equisetum arvense), which was an experiment on its own. Then there were the dyeing tests - a first trial at reconstructing some early modern recipes for dyeing knitted caps, with the three great providers of red: madder, cochenille, and kermes. Micky had an experiment with madder as well, a spin-off from the fake purple research, using madder root that had been pre-treated in different ways.

And then, of course, there was the Madder Baselines experiment. We had the staggering number of 35 different water samples for testing the dyeing outcome and the influence of the water on the dye result... so that was huge, and ate up all the time available, and then some. Especially since the experiment went not just as planned.

It was rather clear when we were getting ready that the amount of goods was very large for our small beakers - but there's the decision to make between having very small samples (where any fluctuations in amounts of madder, or the quality of the teaspoonful you are using compared to the quality of the second teaspoonful for the next sample will make more of a difference the smaller your samples are) or having larger samples and larger amounts of dyestuff but running the risk of uneven dyeing. 

We decided to go for larger samples and the risk of spotting... which, in retrospective, was not a good decision, as spotting was very, very prominent. So we went for the afterbath - which was another mordanting run, and another dye run. That did not satisfy us with the results, so we decided to use the waters that we had more of to do a second run, with more liquid and thus less of a risk of uneven dyeing. Another batch of samples to make, another mordanting run, another dye run.

And then we had to test the different madders that we got - mordanting and dyeing in de-ionised water, to make things all even and comparable. 

Long (very long!) story short: We did get to see some differences depending on the waters used, but they were not as pronounced as we would have expected them to be. There's also a difference between the different madders. Now the last factor that would need to be checked is... the Human Factor. Because the speed with which you heat your dyebath, the temperature, they also might make a difference. 

Fortunately, most of the Forum participants volunteered in taking part of this experiment, and dyeing a sample at home. Which is why this happened today:

I harvested some more madder from the garden yesterday, and today it was dried enough (I sped the process up a bit) to be ground, and now it can finish dyeing... and then there'll be a test run of my instructions for the volunteers, and then these can be sent out. 

And then we'll see. I am very, very curious if there will be differences visible - after all, it's the same madder, the same samples, the same mordant, the same instructions, and the same water (de-ionised water for the win!). 

What's your guess? Will we have differences? Or will it all look the same? 

Stuff is accumulating here and there, I am checking the lists, getting things ready (such as filling liquids into all kinds of containers), doing a bit of writing work (with a lot of help from the little cat, who is hanging out on my desk and napping on my arm), and generally getting very excited about the things to come.

Most has arrived in time, or gotten finished in time, such as the Equisetum Arvense slurry (which was made according to instructions for gardening use, where it gets to shine as plant-strengthening potion, but in my case it's of course intended for mordanting tests) and the kermes (yes, there's actually a chance I will see kermes being used!) and the bran water (thanks to my trip to Romania, where I got the hints on how to make it). It looks like the bran has a pH of about 4 once it's nicely fermented, which is about what we got when we put the alum into our mordanting baths for the Pompeii dyeing experiment.

There's something like a rough schedule as well - knowing how dye experiments go, it makes no sense to plan it in excruciating detail. It looks like we'll have enough space and enough stuff if we figure out the logistics on site properly. (Run a little practical conference on dyeing, with a bit of an experiment here and there, and you might suddenly find yourself the proud owner of 50 lab glass beakers. You know. As you do.)

With that said... I will be off the blog tomorrow to give me a little more time for getting things sorted and packed up - and then, as you've probably guessed, there will be blog silence for the Forum week and some recovery time afterwards. I will be back on November 22! 

Heaps of things to take to the Forum, some larger, some smaller, are turning up at different spots hereabouts - sometimes three in a room, sometimes one. There's a stack of books, there are tools, there's a few canisters now to take the liquids along without them exploring the car illegally... there's materials and extra stuff and the whole documentation logistics like the camera and tripod and so on and so on.

I've started a second batch of bran water, using the starter from the last go, which will be fermenting for a few days now. I am also, since this morning, the proud owner of a lot of 250 ml lab glasses - of which a lot can fit into a single canning pot, and thus we can run a good number of sample dyeings at once.

 A waterbath is the tried-and-trusted method to have the same temperature curve for all the samples, and to do them at the same time. We've used that method before when doing dyeing experiments, but with the 1 l beakers, and only 5 or, at the most, 6 will fit into the pot.

If my math and rudimentary drawing skills are correct, we'll be able to fit 20 of the 250 ml beakers into the same pot easily. And though using the small pots means that we'll only be able to do very small samples, and run the risk of them being dyed not completely evenly, having the large number for a run seems, to me, to be an acceptable trade-off.

This, by the way, is one of the bits that I find both exhausting and fascinating when planning and doing archaeological experiments: The myriad decisions that you have to make. Smaller jars or larger ones? Sometimes things and processes don't scale well, and there's a point at which it becomes difficult to measure the very small amounts, plus the inevitable tiny differences will have a much larger impact. Natural substances (like raw, fresh tartar) or processed? The natural stuff or raw stuff may have components that change the outcome, but the processed pure form means it will be possible to repeat the experiment better. What to document, and how often? Sometimes taking measurements will disturb the process, but not taking them means you'll stand there lacking data. How many variables to test, and which ones are the important ones?

So, so many questions. There's a decision to make at every single step, and an experiment has a lot of steps, even if it's a simple one. So you make the decisions, and then you stick with them, and you hope they were the right ones!

(No blog post tomorrow, by the way - it's a holiday here.)

Well, the plan for the Madder Baselines is about done - the rest of the planning will have to be done as soon as we know how many samples there will be to handle, and then go for a last check through the long list of steps - before following them through to, hopefully, a nicely colourful end.

Meanwhile I have a second template to turn into a plan and protocol: the template for a mordanting experiment. Common Horsetail is said to contain quite a bit of alum, so it is in theory a replacement for mineral alum which may not have been available everywhere. However, it's not really clear if the horsetail is really suitable for this, mostly because there's no recipe that tells us about amounts necessary, or if there was any other preparation done before using it. Or at least I have not been able to find any...

So the idea was to try out if the plant will work as a mordant, and if yes, how much of it is needed. Because even if it's available, if you need ten times the amount of wool weight to have enough alum, well... that would mean 10 kg of the dried plant for a single kilo of wool, and if you've ever woven fabric, you know that a kilo is a puny amount.

I can think of three different methods of using the plant straight away: as it is (just dried, then soaked, and maybe boiled a bit previously to better get out the contents), fermented, or (which would also reduce the bulk of it) burnt to ashes (which should still contain the metal, though maybe in a different form). 

Obviously, the burning and the using as is do not need extra prep time, but the fermenting does. I'm happy to report that the 100 g of plant that I put into 7 litres of rain water are doing what they are supposed to be doing: Making bubbles and working on changing their smell.

It's not an unpleasant smell (at least not yet), but it is definitely much different from the smell it had at the start (like dried horsetail, but thank you, Captain Obvious). I'm very, very curious already to find out how (or if!) all this will work!

Planning an experiment is like planning a reconstruction - it's really, really easy to forget something. Where something can be a minor detail or, if one is a bit unlucky, something that seems like a minor detail at first but turns out to be rather crucial. 

 I've also found, in the number of experiments that I've either run, or co-run, or been somehow a part of, that it is quite easy to forget that one had planned to make photos at a specific point, or that something has to be changed and this all results in a number of hectic notes that are scribbled somewhere.

Part of that is just business as usual. Not every experiment runs as planned, and sometimes adjustments have to be made on the fly. But I found that good prep is really helpful... and that having a good template for the planning makes the good prep easier.

I've recently updated the experiment planning template on the Textile Forum website, and if you're interested, you can find it here. In case you are using it, please let me know if you have any comments or feedback - I'm always happy to hear about this!

Things done yesterday and today? Found out that there are test strips that will give an indication of stuff in water, including the interesting bits such as copper, iron, nitrites and nitrates, lead, hardness and so on. There's some that will give you 6 values and some that give 14 and some that give you 16 - so we're going to have the 16-value strips for some indication of how different our water samples are.

These are, of course, not very accurate and not comparable with a proper lab analysis of water, but it will be a quick and dirty solution to get indications of differences, and have a rough documentation of them. And then it's always possible to take a bit of the water and hand that in for a proper analysis, should it turn out that it would be really interesting. (Tap waters in Germany usually have an analysis available from the water works, but that might not be the case everywhere, and for the spring waters and creek waters, well, there's no analysis of them anyways.)

So that bit of our experiment is now sorted as well; other supplies and ingredients are on their way, the experiment protocol/guideline and documentation sheets are being worked upon, details are discussed, tea is being consumed, oh, and I've packed some goods to send off so a post run is on the agenda now as well.

I can't believe that it's less than two weeks from now that the Forum starts...