The idea they share
Schoppel dyes the fibre before it is spun, in long runs of colour, so the finished ball changes shade slowly along its length — metres of one colour fading into the next — rather than in the short stripes of a self-striping sock yarn. A single 100 g ball takes a sock, a hat or a scarf through a whole gradient. The differences between the lines are in how many plies carry that gradient, and at what weight.
Zauberball
The original: a single-ply fingering, 75% superwash wool and 25% nylon, 100 g and about 460 yards. One gradient runs through the ball, so the colour changes in clean, slow bands. A pair of socks from one ball will not match each other exactly, which is the charm or the problem depending on the knitter.
Zauberball Crazy
The best-selling one, and the one most people mean. Two plies, each carrying its own gradient, twisted together — so at any point the strand is two colours, and the fabric marls and shifts through combinations that never repeat. Same fibre and put-up as Zauberball, same fingering weight. It is a sock yarn first, and a one-ball shawl second.
Zauberball Starke 6
Zauberball Crazy's heavier sibling: the same two-ply construction and wool-nylon blend at a DK-to-sport gauge, in a 150 g ball of about 437 yards. Faster socks for boots, and the weight for a hat or a cowl with the same marled gradient.
Zauberball Crazy Cotton
The plant-fibre version — 100% organic cotton at DK weight, 100 g and 230 yards — for people who cannot wear wool and for summer shawls and tops. It has the two-ply marl but not the elasticity; swatch before planning a garment.
Edition 3
Not a Zauberball, though it is often shelved with them. Three plies of extrafine superwash merino, no nylon, at DK weight in a 50 g ball, dyed so each ball moves through three related shades. Softer than the Zauberballs, smoother, and the one for a sweater or a baby blanket where the wool-nylon hand would be wrong.
Which to buy
Socks: Crazy, or Starke 6 for a thicker sock. A one-skein shawl: Crazy, or Crazy Cotton in summer. Anything against the skin, or a garment: Edition 3. And if you want the clean, slow bands of colour rather than the marl, the original Zauberball.