A supplier's specification sheet can tell a manufacturer the GSM, coating type, roll length, and other technical details. It cannot fully predict how the interlining will behave with a particular shirt fabric. That is why sample testing should happen before a large production order, especially when introducing a new supplier or fabric.
The first step is to fuse a small piece of non woven fusible interlining to the actual shirting material. Avoid relying solely on a generic test fabric because weave density, finishing treatments, colour, and fabric composition can change the bonding result. Use the same fabric intended for production and follow the planned pressing conditions.
Once the sample cools, inspect it carefully. The adhesive should create a consistent bond without obvious bubbles, lifting, or uneven areas. Turn the fabric over and check whether the interlining affects the visible surface. Then bend and flex the sample to see whether the fused layers move naturally together.
Washing provides an even more useful test. Shirts commonly undergo frequent laundering, so a bond that looks perfect immediately after pressing may still fail later. A suitable non woven interlining fabric should maintain adhesion and should not become excessively brittle or stiff.
Manufacturers should also compare new batches with previously approved material. Check hand feel, stiffness, colour, GSM, and roll length against the purchase specification. These checks can identify variations before production begins.
Testing may appear to slow down the manufacturing process, but it can actually save time and money. Discovering a bonding problem after hundreds of collars have been assembled creates far more disruption than testing a small sample beforehand.
