A key property for a product is it’s Shipping Weight that can be different from its Product Weight. The Shipping Weight is used to calculate how much a product contributes to the shipping cost, which is traditionally based on weight. By default, the values are the same and only edge cases need adjustment.
Increasing Shipping Weight for Low Volumetric Weight items protects against underselling shipping and incurring uncovered distribution costs.  Couriers typically charge per box, up to 30Kg.

E.g., 2 products with similar weight occupy different amounts of the box.

A) High Volumetric Weight, Fragile Glass – needs protecting, Weight = 500g, Ship Weight = 600g

B) Low Volumetric Weight, Robust – no packaging, Weight = 500g, Ship Weight = 8Kg