GRS Recycled Content through Differential Process Loss

This is a single-stage balance and a real supply chain has several, each with its own differential loss - opening, carding, combing, spinning, and every one of them favours the longer fibre. The shortfall therefore compounds through the chain rather than occurring once, and a blend that certifies a point low at the yarn stage can be further adrift at the fabric. Run each stage separately where the chain is long. The loss figures should come from the mill waste record separated by stream, which requires that the two streams are actually tracked separately somewhere - and on a line running a pre-blended lay-down they are not, which is why the honest answer for many spinners is that the differential is unknown rather than zero. Note also that the certified quantity is governed by the reconciliation rules of the standard itself and not by this arithmetic: certification schemes work on transaction certificates and permitted tolerances, and a mill whose physical mass balance is sound can still fail an audit on documentation, or pass on documentation while its physical balance drifts. Use this to set the batching, not to satisfy the auditor. Recycled content is also not a proxy for environmental benefit, and a blend pushed to a high recycled percentage at the cost of yarn strength, more breaks and more waste downstream can be worse on every measure that matters.