Wet felting is an enjoyable and fast craft. In under thirty minutes you can turn a hand-carded batt into a hat, a scarf, a bag or a pair of gloves.
What beginners often do not realise is that not all wool is equal. You have probably seen the term “microns” mentioned, and every experienced felter knows that the micron count of the wool has an enormous influence on the result.
What a micron is
A micron is a unit of measurement for the diameter of a wool fibre – one thousandth of a millimetre. The lower the number, the finer the fibre.
Fine merino sits somewhere around 18 to 21 microns. A medium wool might be in the high twenties. Coarse carpet wools run into the thirties and above.
Why it matters for felting
Two reasons, and they pull in different directions.
Fineness affects how it feels. This is the one people notice. Below roughly 25 microns, wool is comfortable against most skin. Above about 30, it prickles – not because it is scratchy in some vague way, but because coarser fibres are stiff enough to press into the skin rather than bending against it.
For anything worn against the neck or face, this is the whole decision.
Fineness also affects how it felts. Finer fibres have more scales per unit of length and tangle more readily, so fine wool felts faster and produces a denser, smoother fabric. Coarser wool felts more slowly and gives a firmer, more open result.
Choosing by project
Hats, scarves, gloves and anything worn next to skin: use fine wool, merino or similar. The comfort matters more than anything else, and the fast felting is a convenience.
Bags, slippers, rugs and vessels: a coarser wool is genuinely better. It gives a stiffer, hard-wearing fabric that holds a shape, and nothing is touching skin.
Using fine merino for a bag produces something soft that will not stand up. Using coarse wool for a scarf produces something nobody will wear. Both are common beginner mistakes and both come down to micron count.
Practical notes
Blends of two micron counts can work well – a coarser core for structure with a fine surface layer for feel.
Be aware that finer wool felts faster than you expect. If you are used to a medium wool and switch to merino, check the work early and often, because it will shrink further and quicker than you are anticipating.
Buy from a supplier that states the micron count. Many do not, and “wool tops” on its own tells you almost nothing about how the piece will turn out.
