Woven interlining should be tested for shrinkage when a production change or a higher risk of dimensional problems makes the result important. The purpose is to identify potential size changes before bulk cutting and fusing rather than after the material has already been incorporated into production.
A new interlining batch is one situation where testing can be useful. The same applies when using a new outer fabric because differences in fibre, weave or finish can affect how the two materials behave together. Changes in garment construction can also alter the exposure of the interlining during production. New suppliers or material specifications introduce another variable that may need to be checked.
Production and finishing changes are also relevant. If the garment process introduces different levels of heat, moisture, pressing, steaming, washing or other finishing conditions, the interlining should be evaluated under those conditions. High-volume production can make small dimensional changes more significant because the same issue may affect a large number of garments.
A practical decision process starts by identifying where the interlining will be used and which production steps it will experience. The next steps are to consider potential shrinkage exposure, test a representative sample, measure dimensional change and check compatibility with the outer fabric. The result can then be used to approve the material, adjust the process or select another option. This approach is especially useful for dimension-critical garments where there is little room for dimensional drift. Testing before bulk production gives manufacturers an opportunity to identify problems while changes can still be made.
