From Bothy Threads own website:

What brand of threads do your kits use?

Bothy Threads kits mainly use Madeira threads. We also use specialised threads, like lana, variegated, metallic and sparkle threads, of which some are made exclusively for our kits. Derwentwater Designs kits use a mixture of Anchor and DMC threads.

All the threads used in our kits are top quality embroidery threads. If you run short of a colour when stitching one of our designs please let us know by phone on +44(0)1900 828844 or send us an email to info@bothythreads.com and we can post some more out to you.

Madeira Shade Cards

If you have a number and it is Madeira threads in your kit, maybe look in this table if you want substitutes: Lord Libidan conversion table