What about Drummond of Perth? How far back does that design go?

Thanks for the list. It's pretty cool.

A few of those appear in 18th century portraits which are familiar to me. It would be nice to have the tartans sorted by source

1) taken from a portrait painted prior to 1746

2) taken from a piece of surviving cloth known to date to before 1746

3) ?? what other specific sources of tartan designs exist? Pre-1746 thread counts written down by a weaver?