I'd say it depends what size you're getting. I had a small Sandy's for Iris, which fitted her from birth to well past a year old; I sold hers on before she outgrew it. Ours was bamboo, but it still had to be boosted as Iris got bigger, so for that reason I'd avoid small cotton. But I have bought xsmall cotton Sandy's to use with this baby. I don't think they'll last for long, so there's no need for them to be bamboo (he'll outgrow, rather than outpee them, I think). If I'm wrong, I'll boost. No drama.