Inspired by the success and popularity of the
spermaceti thread, the idea came to me for another high value marine animal product - the colour of the Caesars - Tyrian purple!
Also known as
imperial purple (which would likely be the in game name to avoid real-life location names) it was an extremely valuable reddish-purple dye used by ancient cultures around the Mediterranean Near East and Mexico. It was extracted from the
murex snail in a messy, dangerous and frankly disgusting process, which to me sounds
extremely dwarfy. Here's the process according to
Pliny the Elder:
The most favourable season for taking these fish [i.e., shellfish] is after the rising of the Dog-star, or else before spring; for when they have once discharged their waxy secretion, their juices have no consistency: this, however, is a fact unknown in the dyers' workshops, although it is a point of primary importance. After it is taken, the vein [i.e., hypobranchial gland] is extracted, which we have previously spoken of, to which it is requisite to add salt, a sextarius [about 20 fl. oz.] about to every hundred pounds of juice. It is sufficient to leave them to steep for a period of three days, and no more, for the fresher they are, the greater virtue there is in the liquor. It is then set to boil in vessels of tin [or lead], and every hundred amphorę ought to be boiled down to five hundred pounds of dye, by the application of a moderate heat; for which purpose the vessel is placed at the end of a long funnel, which communicates with the furnace; while thus boiling, the liquor is skimmed from time to time, and with it the flesh, which necessarily adheres to the veins. About the tenth day, generally, the whole contents of the cauldron are in a liquefied state, upon which a fleece, from which the grease has been cleansed, is plunged into it by way of making trial; but until such time as the colour is found to satisfy the wishes of those preparing it, the liquor is still kept on the boil. The tint that inclines to red is looked upon as inferior to that which is of a blackish hue. The wool is left to lie in soak for five hours, and then, after carding it, it is thrown in again, until it has fully imbibed the colour.
The process goes quite indepth, so I'll try to sum it up in simpler, dwarfier terms:
1. Obtain murex snails, living or dead. Obviously if you want a renewable industry, you'll want live ones, otherwise eventually you'll fish them to extinction.
2. The live snail is prodded/goaded into releasing
raw murex extract as a self-defense mechanism; this could be done through the milking labor. There may be problems with milking an aquatic creature, though. If it's an insurmountable challenge, we can simply skip this step and go to step 3.
3. The extract is boiled, whether the milked fluid on its own or the entire still alive snail, in a great tank of water, with the addition of salt, and then left to decompose. If the latter option is chosen, the snail obviously dies and cannot be reused. This would require fuel and some sort of salt analog, and would be performed at a dyer's shop if that's at all possible. This would also create miasma, so whichever workshop this reaction uses would have to be isolated from the rest of your fort, and the dyer should definitely get some really nice furniture in their room to make up for having to work in the stench.
4. We could consider the dye finished at that point, but the excerpt mentions "inferior red dye"; it could be set up so the first boiling reaction gives us
red murex dye, which while moderately valuable would not be worth leaving at that stage. It would have to be processed once more to give us
imperial purple dye.To summarise the reactions required would be:
1. (Optional) Milk murex snail >> raw murex extract.
2a. Raw murex extract + coal + salt? >> red murex dye.
or
2b. Raw murex snail + coal +salt? >> red murex dye.
3. Red murex dye + coal >> imperial purple dye.
Now the question is, is any of this even remotely possible? Can one even obtain dye from an animal, seeing as all dye sources in the vanilla game are plants? Could these extra reactions be added on to the dyer's shop, or would a new workshop be needed? I'm not experienced in reaction raws but I'm willing to give it a shot once I get an idea of what people think.