The antonyms for the phrase "had a weight of" could include "was weightless", "had no mass", "was insubstantial", "was weight-free", or "had a feather-lightness". These contrasting expressions convey the opposite meaning of having a heavy or burdensome weight, suggesting a sense of lightness, ease, or insignificance. These antonyms might be used to describe objects or experiences that are intangible or lacking in substance, such as a fleeting thought, a fleeting feeling, or a fleeting moment of joy. Alternatively, they could refer to physically light or buoyant objects, such as a colorful balloon or a delicate butterfly.