Where to find a spider web?

[N]

A mimic I'm playing has basically hit a brick wall. I need a spider web but I can't seem to find one.

tomespoiler.jar shows the following info:

A Spider Web [1,+0] (1d1) (+0,+0) (yellow ()
Level 5, rarity 130, weight 3.0 lb, cost 100

From my reading of this that means it's most likely to spawn on dungeon level 5, but is obscenely rare. So does that mean I should just keep grinding the barrow downs looking for it? Or is there a better place to look for it? (There isn't anywhere I can just buy one is there?)

I don't care about it's enchantment value, I just need one.

[Yottle]

You might try the sandworm lair. Also, as you go deeper the various mimicry cloaks become more common, in my experience. Level 5 seems sort of high to find one. Sometimes they show up in the black market.

[N]

Found the following entry in mimic.lua

["obj_name"] = "Spider Web",
["desc"] = "Spiders are clever and become good climbers.",
["realm"] = "nature",
["level"] = 25,
["rarity"] = 50,

I've moved to the sandworm lair. I've found one cloak so far (not the one I need). I'll keep looking.