From Lab Dip to Bulk: Managing Colour and Shade Batches

The Lab Dip Is Not the Bulk

A lab dip is dyed in a small beaker on a sample machine. Bulk runs in a jet dyeing machine with a completely different liquor ratio, agitation and heating curve. The same recipe does not land in the same place at the two scales — every mill has a conversion step, and that step is where shade drifts.

This is normal and manageable. What is not manageable is approving a lab dip without agreeing how bulk will be judged against it.

Agree the Tolerance Before You Approve

“Match the lab dip” is not a specification. Put a number on it:

• Light source — which illuminant the comparison is made under (D65 and TL84 are the common pair; approving under one and inspecting under another is how metamerism disputes start)
• Tolerance — a dE value, or an agreed grey-scale rating, not “looks right”
• Who judges — mill lab, third-party lab, or your QC on receipt

Write it into the order. A shade argument at shipment with nothing agreed in writing always costs the buyer time.

Shade Batches Are Not a Defect

A large order is dyed in several machine loads, and loads differ slightly. A responsible mill sorts the rolls into shade batches and labels them so your cutting room keeps one batch per garment.

The failure mode is not the batching — it is mixing batches inside one garment: a front panel from batch A and a sleeve from batch B, visible under store lighting even when both are inside tolerance. Ask for shade-batch labelling on the rolls and tell your cutting room to respect it.

Where the Time Actually Goes

Budget realistically: lab dip submission and approval typically runs one to two weeks with revisions, bulk dyeing another two to three, and a re-dye adds a full cycle. Compressing the approval stage is what pushes a re-dye onto the critical path.

Send accurate colour standards — a physical swatch or a Pantone TCX reference, not a screen colour — and approve promptly. Most colour delays are approval delays, not dyeing delays.