Pre-shrinkage testing becomes particularly useful in high-volume garment production because a small dimensional change can affect a large number of finished pieces. Testing a representative sample before bulk work provides an opportunity to identify potential problems before they are repeated across an entire production run.
The dimensional stability of woven interlining depends on several factors. These include fabric construction, composition, processing conditions, finishing methods, garment construction and outer fabric compatibility. Heat, moisture, washing, steaming and pressing may all be relevant depending on the production route.
Testing should take place before bulk cutting and fusing. A representative sample can be taken from the intended batch, with its original dimensions recorded before processing. The sample is then exposed to the relevant production conditions and allowed to settle before being measured again.
The result should be compared with the production requirements of the garment. The fused pair should also be checked for rippling, puckering or distortion because dimensional differences between the interlining and outer fabric can affect the finished appearance. New batches, outer fabrics, garment constructions, suppliers, material specifications or finishing methods can create a new testing requirement. Keeping a swatch of the tested and approved lot can provide a reference for future batches. The purpose of the test is to identify potential dimensional problems on a small scale, when the production team can still approve, adjust or change the material before the issue reaches bulk production.
