What does "soft bump" mean?

Stuffed in soft leather; The way the artifact expands. \x0d\ The origin is clear. Li's History of Civilization, Chapter 49: "See the rattan baskets and so on, which are bulging with many things." Example \x0d\ Throw their bulging small bags of gold on the counter. \x0d\ usage as attribute and adverbial; A stuffed body.