Seal integrity problems don’t usually show up during the first clean run; they show up after the first restart, the first roll change, or the first speed ramp. This article walks through a practical way to keep seals stable in flexible packaging by working inside a real seal window, using defect signatures to aim troubleshooting, and building a control plan that holds up across shifts. You’ll also see how Unified Flex supports consistency on the rollstock side with COF, thickness, heat-seal, and tensile testing, plus print inspection, so you can spend less time chasing drift and more time running product.