Heat and moisture are two important conditions to consider when testing woven fusible interlining. During garment production, the material may encounter heat through fusing, pressing and steaming. Moisture can also be introduced through steaming, washing or other finishing processes. These conditions can influence dimensional stability.
The response is not determined by heat or moisture alone. Fabric construction and composition can affect how the interlining behaves. The outer fabric also matters because the two materials are bonded together in the garment. Different fibres, weaves and stretch characteristics can affect how the fused combination changes size.
Fusing conditions should therefore form part of the test. Temperature, time and pressure all contribute to the conditions experienced by the interlining. If the garment later undergoes washing, steaming, dry cleaning or another finishing process, those conditions should also be considered. The test should reflect the actual production process as closely as possible.
A representative sample can be measured before processing and again afterward. The sample should be allowed to cool and settle before the final measurement. There is no universal temperature, duration or dimensional-change limit that applies to every woven fusible interlining combination. The relevant conditions depend on the material, production process and garment. Testing under the actual conditions therefore provides a more useful result than relying on a general assumption about how heat or moisture will affect the material.
