Built around the packed set
Cosmetic packaging usually holds a mix of shapes: bottles, tubes, compacts and applicators in one pouch. The internal size comes from the packed set, not from the largest single item — a pouch sized from the biggest bottle alone generally will not close over the whole kit. Decide early whether it lies flat or needs a gusset to stand, because a gusset is a different pattern rather than a larger version of a flat pouch.
How the snap closure behaves
A snap closes positively and stays closed, which matters for anything carried loose in a bag or shipped without an outer box. It adds a hardware component and one more position that has to be right — snap placement is set from packed thickness, so a snap positioned for an empty pouch will strain or fail to reach when the pouch is full.
Open and close it repeatedly on a packed sample. Snap feel and retention after repeated use are not visible in a single inspection.
