What if a batch is defective?

Report it to your account manager - the complaint rules are set out in the contract.

If the defect is our fault, for example through negligence or an oversight, we handle the complaint on our side. If it is a hidden defect in a material, it depends on who supplied it: we claim against suppliers for materials we ordered ourselves, and for materials you supplied we help you prepare the claim - with the production report, photos and other evidence.