Why does sample-to-bulk consistency change after switching factories?

Sample-to-bulk consistency can change after switching factories because every manufacturer has different pattern methods, fabric sources, sewing operators, machines, finishing processes, and QC habits. Even when the tech pack is the same, the new factory may interpret measurement points, seam allowance, shrinkage, rib tension, logo placement, or pressing differently. This is why brands should not rely on one approved sample only. A safer process includes PP sample approval, TOP sample checks, inline QC, final inspection, and side-by-side comparison with the previous approved bulk sample. For products such as jackets, hoodies, tracksuits, cargo pants, and denim, these checkpoints help protect the fit and quality customers already expect.