Most damage to alpaca happens in storage rather than in wear. Six months in the wrong box does more harm than a winter of use, and it is entirely avoidable.
What the moth is actually after
Adult clothes moths do not eat anything. The larvae do the damage, and what they want is not the fibre itself so much as what is on it: skin cells, food traces, sweat, hair oils. A dirty jumper is a meal. A clean one is much less interesting.
That single fact drives everything below. Wash before you store, every time, even when the garment looks perfectly clean. It is the most effective thing you can do and it costs nothing.
The method
1. Clean everything first
Hand wash cool with a wool wash, press the water out in a towel, dry flat. Make sure it is completely dry before it goes anywhere. Damp fibre in a sealed container grows mould, which is worse than moths.
2. Fold, do not hang
Hanging a knitted garment for six months stretches the shoulders out of shape permanently. Fold everything. If you must hang a woven coat, use a broad shouldered hanger.
3. Seal it
An airtight container or a good zip bag. Moths cannot lay eggs on what they cannot reach. Cardboard boxes are not sealed and neither is a suitcase with a zip.
If you use vacuum bags, do not crush the air out completely. Compressing fibre for six months flattens loft and it does not fully recover.
4. Somewhere dark, dry and stable
Under a bed or in a wardrobe is fine. A garage or a roof space is not, because both swing between hot and humid and that is hard on the fibre and inviting to insects.
What works, and what is folklore
Cedar. Genuinely repels moths to a degree while the oil is still active, which is a year or two at most. Sanding a cedar block occasionally brings the smell back. It is a deterrent, not a treatment, and it does nothing about eggs already present.
Lavender. Pleasant. Mild deterrent at best. Do not rely on it alone.
Naphthalene mothballs. They work, and the smell gets into soft fibre and stays there for a very long time. Most people who use them once do not use them twice.
Freezing. Effective on eggs and larvae if you do it properly: seal the item, freeze for at least a week, take it out, let it come to room temperature, then freeze again. The second cycle catches anything the first missed. Useful if you suspect an infestation.
Airing and light. Moths dislike disturbance and light. Simply taking things out mid summer, shaking them and putting them back does real good.
Storing raw fleece and unspun fibre
Different problem, same principle. Raw fleece has more organic matter in it and is more attractive to insects than a finished garment.
- Never store raw fleece damp.
- Breathable bags, not sealed plastic, for unwashed fleece. It needs air.
- Washed and dried fibre can go into sealed containers safely.
- Check it. Fleece put away and forgotten for two years is how people lose a whole clip.
A good habit is to open every fibre container once through summer and look. Frass, which is the fine dust larvae leave behind, is the early sign, and it looks like sand at the bottom of the bag.
If you find damage
Isolate the affected item immediately, in a sealed bag. Freeze it on the cycle above. Then empty and clean the entire storage area, because eggs will be in the corners and the seams of the container, not just on the garment.
Check everything else stored nearby. Moths do not confine themselves politely to one jumper.
The short version
Clean, dry, folded, sealed, dark. Look at it occasionally. That is the whole thing.
See also: the complete guide to caring for alpaca products.
Our raw fleece ships in a breathable bag for exactly this reason. If you are not going to prepare it within a few months, open the bag and check it now and then.