Tartan Adoption in the Borders

[davidlpope]

I've recently been re-reading George MacDonald Fraser's "The Steel Bonnets". I'm intrigued by the question of when clan tartans were officially approved by the chiefs of the Borders families.

It seems that many of the most powerful Borders families were included in the VS. When did these designs gain approval from these Borders families, given that this wasn't traditional in that area?

Did the Borders chiefs officially sanction these tartans? Did they register their designs in a manner similar to the HSL?

Any suggestions for books that deal with this issue are appreciated. Thank you for your help.