Merino vs Regular Wool

One variable explains everything

Merino is not a different substance from other wool. It is wool from a particular breed of sheep, and what distinguishes it is fiber diameter - merino fibers are finer than those of most other breeds.

Fiber diameter is measured in microns, and it determines almost everything else. A fine fiber bends when it meets skin instead of pushing into it, which is what softness means. A fine fiber also breaks more easily and works its way out of a yarn more readily, which is what pilling means. Same property, two consequences.

The comparison

Where merino is worth the money

• Anything against bare skin. Cowls, hats, baby garments, next-to-skin sweaters.
• Small projects. A cowl is one skein. This is where an expensive yarn is genuinely affordable.
• Shawls. Fine fibers drape better - see best yarn for a shawl.
• Anyone who has decided wool itches. It is very often coarse wool rather than wool as such, and merino is the test.

Where regular wool is the better buy

• Outerwear. Worn over a shirt, prickle is irrelevant and toughness is not.
• Colorwork. A crisper, grabbier fiber holds floats better - see best yarn for colorwork.
• Felting. More controllable, and the finished felt is tougher - see best yarn for slippers.
• Anything with cables or texture. Crisper stitch definition.
• Blankets and rugs. Nobody's neck is involved and durability is everything.
• Learning. It costs less, and a first sweater is not the place for a yarn you will be anxious about.

The superwash complication

Most merino sold in yarn shops is superwash-treated, which is a second variable stacked on top of the first.

Superwash processing removes or coats the fiber scales so the wool cannot felt. It also smooths the surface, which makes the yarn feel softer still, and removes some elasticity and surface resilience. So a superwash merino is soft twice over and durable neither time.

That is not an argument against it - washability is worth a great deal on a garment somebody else will launder. It is an argument for knowing that you are buying two treatments rather than one. Our superwash vs non-superwash page covers the second one in full.

Blends, which is what most people actually buy

The commonest wool on a craft shop shelf is not merino or regular wool. It is a wool-acrylic blend, usually around 20 percent wool.

At that ratio the acrylic dominates the mechanical behavior: the yarn washes and dries like acrylic, and the wool contributes warmth and a little springiness. It is a genuinely sensible product and it is not a substitute for either fiber in this comparison. Wool-acrylic blends has the arithmetic.

Merino pills, and that is not a defect

The single most common complaint about merino garments is pilling, and it follows directly from the fineness people bought it for.

Finer fibers means more fiber ends per inch of yarn, and more ends means more to migrate to the surface under friction. Choosing a firmly plied merino helps, as does a worsted-spun rather than woolen-spun preparation - see yarn ply and twist explained and why yarn pills.

How to decide, in one question

Will this touch skin that has nothing over it?

If yes, buy merino, and buy less of it by choosing a small project. If no, buy regular wool and spend the difference on more yarn. That single question resolves the great majority of cases, and the exceptions - colorwork, felting, hard wear - all push toward regular wool anyway.