I thought the fabric (aside from the cape, which is too far from his aura) was invulnerable because of being so close to his aura. Not to mention, in "Don't Tug on Superman's Cape" she had to get whole new bolts of fabric just to make almost all new uniforms (how one survived long enough for Superman to make an appearance at the Lake's is a question I don't have an obvious answer for... maybe it was in the dirty clothes pile?)

CLARK: No. I'm just worried I'm a jinx.
JONATHAN: A jinx?
CLARK: Yeah. Let's face it, ever since she's known me, Lois's been kidnapped, frozen, pushed off buildings, almost stabbed, poisoned, buried alive and who knows what else, and it's all because of me.
-"Contact" (You're not her jinx, you're her blessing.)