After seeing on the database it's stating that the weight of the cape is 0.40

 

How ever in-game:

 

 

Hope this helps :)

And hopefully I posted in the right area :o

Thanks for your submission, loldielol!

 

I understand how this could be confusing, but upon equipping the cape your weight will show -6kg as the cape's function is to reduce your weight, but the actual cape itself only weighs 0.4kg. The only way to find the weight of an item that reduces weight is to check it's weight while it isn't equipped.

The cape itself weighs 0.4kg, even though it reduces weight by -6kg when worn. If you were to have nothing equipped and nothing in your inventory except the cape, it would help you see what I mean by this.

 

I hope this helps to clarify the confusion :P

 

Let me know if I can help with anything else. I'm going to lock this, but please definitely PM me if you have anything to add to this.