Before there was Anchor threads they were called Clark's threads and they were manufactured at the Anchor Mills in Paisley, Scotland.  The Anchor brand did not come into being until 1866 when the Clark family adopted the Anchor brand for their embroidery threads manufactured in Paisley, Scotland. Embroidery threads came into being circa 1812 when supplies of silk became unobtainable in the UK due to a blockade by Napoleon. Two weavers, James and Patrick Clark, turned their attention to cotton and managed to produce yarn which was sufficiently fine, smooth and strong to be used instead of silk for weaving and embroidery.  

This box of Clark's Stranded Artificial Silk for Embroidery contains 8 skeins of purple variegated thread.

As a vintage item once it is sold there is no more stock.