Wolf yarn is a core-less core-spun yarn, named by Judith Mackenzie because it kept the wolf from the door. It is technically challenging but once mastered it is fairly quick and looks impressive so sells well.
Spinning Wolf Yarn
For a wolf yarn you need a cloud of fairly long fibre, more than 3 inches, your wheel on a low ratio, fairly high take up and good coordination between the two hands drafting both elements alternately.
I have left as singles, plied with a fine yarn silk hankie and plied with itself

Which do you prefer?
I will be running a course on fancy yarns later in the year. To express an interest message me below
Maybe I’ll show you boucle next, another clever yarn and so satisfying,
Let me know what you would like to see on the blog