Note there are two 4 ply yarns in their range:

• Merino and Silk 4 ply
• Merino and Nylon 4 ply

The yarn fortified with nylon is often called “Sock Yarn” on their website and the yarn with Merino and Silk is called “4 ply” but these are not 100% consistent between the website and their Etsy shop so go by content.

From their website at www.sheeponmars.com :

Our range of yarns are all hand-dyed with loving care by Natasha in exciting colourways.

Yarn skeins are individual and generally not named aside from their primary color, for example: “speckled brick red”.