old tartans were "simple and earthy"

[Ninehostages]

In your list of natural sources for dyes you missed out animal. Cochineal and Lac, both Shield Insects, were important sources of red in the 18th century. Urine was used in the extraction of indigotin (blue) dyes, principally Indigo and Woad, it is not a mordant used for fixing dyes.

Yes, artificial dyes can be bright; equally, they can be dull as in the Reproduction range. It is completely incorrect to say that the wide colour palate available to today's weavers didn't exist back then either and the wild and wonderful combinations available now would have been beyond their wildest imaginings. Almost every colour and shade, or ones very similar, were available from traditional natural dyes as this inexhaustive range shows.



There are original examples discussed in these papers An Unnamed late 18thCentury Fancy Plaid and A Joined Plaid dated 1748.

Thanks for the lesson! Since most of the tartans out there seem to date from the Industrial Revolution period (except for a few earlier military ones) I guessed that the big breakthrough was driven by the aniline dyes that appeared in the mid 1800s.