Mentioned in this episode:

DIY Twist Angle Gauge

Online Classes at Sheepspot

Episode 4: Woolen/Worsted

McMorran Yarn Balance from The Woolery

Ravelry's Standard Yarn Weights

Additional resources:

Jillian Moreno, "A Spinner's Compass," Knitty 47 (Spring/Summer 2014).

Jillian Moreno, "The Gist of Grist," Ply (Summer 2014; the twist issue).

Michele Boyd, "Twist Angle," Ply (Summer 2014; the twist issue).

Rachel Smith, "Grist: It is Kind of Really Important," Welford Purls blog.