Most garments should be folded in acid-free tissue in breathable fabric garment bags or acid-free cardboard archival boxes.

WSJ: Ask Teri: How to Keep Moths From Eating Sweaters

That breaks down into a component called free fatty acid and goes into the liver for energy.

CNN: When you're losing weight, where does the fat go?

When you have a lot of excess fat, it generates so much free fatty acid, the liver can't handle it, so it stores it.

CNN: When you're losing weight, where does the fat go?

Serious collectors keep theirs in folders or envelopes made of acid-free paper.

FORBES: Magazine Article

So by building up the concentration of ammonium ions inside its retaining membrane, H. pylori is able to fend off the destructive attentions of the hydrogen ions in stomach acid and thus live free from competition by less hardy germs.

ECONOMIST: Stomach turning | The