Is the "weight --" listed for the Rope of Knots in Ultimate Equipment intentional? It seems odd for it to weigh nothing when all the other magical ropes have weight.
I recognize that this appears to be what the book says, it just seems very surprising. It looks a whole lot like a 40' longer Rope of Climbing, and that rope has weight...
I had the same thought. Perhaps its some additional perk of the magic enchanting a rope of knots that makes it also lighter somehow and easier to carry? I'm using one for a Halfling with a STR score of 8 so I'm not complaining :)