Keeping my cowries in a good condition

[shelley]

I haven't had my cowries long and I've read about how sunlight and dust can ruin them. Is it okay if I keep them sitting on a silk or cotton cloth of some kind which I can then fold over to cover them (so they are wrapped up in bed!) Then I could just whip the top of the cloth off to reveal my pretty rows of shells. I would keep this on my wooden bookcase (but the shells would be touching the cloth not the wood and I live in England so it's not too humid). If they get dust on them is it okay to just use a microfiber cloth that you use to clean camera lenses? If you have any other ideas about how I can keep my 20 very large cowrie please let me know. I found those display boxes but they would work out ridiculously expensive for me! Thanks for any help.