Disclosed are embodiments of a volume control storage bag and methods of making same. The volume control storage bag may have first and second sidewalls, a double-locking closure mechanism with a first closure element extending along the first sidewall and a second closure element extending along the second sidewall, each closure element having a channel and an elongated member configured for interlocking with one another. A gusset is sealed along three sides of the first and second sidewalls, leaving an opening through the closure mechanism and defining an interior space having a specific volume. Corner seals may be formed at the corners of the first and second sidewalls, further reinforcing the double-locking closure mechanism for an airtight and hence waterproof seal. The volume control storage bag may be made of a food-grade polyethylene vinyl acetate blend, approximately 90% or less ethylene vinyl acetate and approximately 10% or less polyethylene.

Systems and methods of indicating to a line worker when there is a defective zipper profile extruded onto a generally flat plastic web while moving in a feed direction in a re-sealable container production line. The system includes a sensor for detecting the defective zipper profile and a web distortion device that actuates in response to the sensor detecting the defect. The web distortion device keeps the web bunched together while it spools onto a roll support device located downstream thereby making it readily apparent to a line worker that the bunched segment contains the defective segment.