canada post shipping label shows different weight

[store223]

does anyone notice shipping label shows different weight?
I filled out Net weight on Customs declaration, and Actual weight on Parcel dimension

On the shipping label, there are Net weight and Gross weight

Gross weight is much higher than actual weight (but I didn't fill that number out, so how was it calculated?)

now if the parcel is returned non delivery or any other reason, which weight will postal service charge the sender with - Gross or Actual?

I think buyer is honest and address is confirmed, but does anyone notice this too or is it  a glitch somewhere? I specifically picked kg and cm, so there is no chance it's lbs and inch measurement.

[ChezF · Accepted solution]

I've had this happen a few times and from what I understand it has to do with "volumetric weight".

It's explained pretty well on the Ebay forums here

http://community.ebay.ca/t5/Seller-Central/Shipping-label-weight-is-wrong/td-p/164527