Polyester vs Nylon for Custom Bags: Which Material Is Better?

Choosing between polyester and nylon looks easy when both appear as small swatches on a sourcing table. The decision becomes much harder once the material has to carry weight, survive abrasion, accept a logo, hold a bag shape, resist rain, match a target price, and remain consistent across repeat production. Two fabrics can both be labeled 600D and still behave very differently because yarn quality, weave density, coating, backing, finishing, and construction can change the final result far more than the fiber name suggests.