User blog comment:FloaterJ/Nitpicker's Nook/@comment-26098790-20150211075206

I assume they have plants they grow to use in materials. Cotton and linen are both common materials that are made from plants. Linen is from flax, if they didn't plan ahead to bring cotton, someone might have brought flax plants for food. There's also less commonly used plants, such as corchorus or hemp (the first is a herb and the second is a food/herb). If needed, they could even get more inventive.

Synthetic clothing obviously couldn't be grown, but being that they are made out of chemicals, they might actually have a way to recyle them. Plant materials will eventually deteriorate, so even if they use it for a long time, it will eventually be unuable. Synthetics may break apart, but they would very slow to deteriorate... Depending on what is being used, they might be able to break the materials down and create something that is like-new (I'm not a chemist that makes fabrics, but we know chemistry is studied on the ark, so this isn't out of the realm of possiblity).

Regardless of whether they can make new material (which like I said, I assume they can), it is still wasteful to float people with their clothes on. I can't excuse it just as a film need, because obviously the filmmakers don't have a problem with stripping people down to their underwear (and let's be honest, no one would want anyone's used underwear).

What IS actually unbelievable about the floating thing, is that they floated people with water inside them (people are about 80% water). Water is the most scarce resorce on the ark, and most definately not something they can grow or get more of. They obviously have to have a way to recycle water out of the body (from the urine). Thus, the "right" way to kill someone would be to dehydrate them (hopefully, not while they are alive), then take their clothes off, then float them. People who died of natural causes would also need to be dehyrated before their bodies were floated.