When a knit cardigan and camisole set is meant to be the “same colour”, approve each finished garment against its own colour standard and approve the two garments together as a pair. Specify each component's yarn, construction and finishing, retain physical references, and compare them consistently under the agreed primary light source and other relevant sources. Two pieces that individually seem close to the same colour card may still fall short of the brand's expectation when placed side by side. A product photo cannot replace physical approval.
This guide is for brands, buyers and quality teams developing adult knit sets. It focuses on the colour relationship between components, rather than set quantities or size pairing. The parties should decide in advance whether the pieces must look the same, what coordinated difference is acceptable, and what evidence is required for each production run. This article prescribes no universal colour-difference tolerance and does not claim that WTBF offers a particular colour-measurement service for any project.
Define the two relationships to compare
The first relationship is between each garment and its individual standard: the cardigan against its cardigan standard and the camisole against its camisole standard. The second is the relationship between the garments: together, do they produce the intended matching or coordinated appearance? If their textures, thicknesses, gloss or fibres differ, requiring an absolutely identical appearance may not be realistic. A coordinated difference can be agreed, but a difference that neither party accepted cannot later be renamed a “design effect”.
Identify each piece's material, yarn or fabric reference, colour, construction, finishing revision and physical standard. Say whether a reference is unwashed, finished or has undergone care. Then agree whether to compare the two side by side or layered as worn, which side faces out and who reviews them. The colour standards and the standard for the combined appearance can be different physical references; the record should make each one's purpose clear. The existing set component pairing guide addresses piece counts, sizes and packing; it does not replace this colour approval.
A match under one lamp may change under another
Colour-measurement supplier Datacolor explains in its introduction to metamerism that a pair of samples can match under one light source but no longer match under another: this can be illuminant metamerism. It concerns the relationship between two samples. Datacolor's guide to light sources describes a change in one material's own appearance when the light changes as a separate phenomenon; do not call both metamerism without distinction. A phone photo or observation alone should not be used to assert the exact cause of a difference.
Choose a primary light source relevant to the project and at least one other source accepted by both parties. Record the equipment, source names and viewing conditions; confirm the actual settings and maintenance with the reviewers. Keep sample orientation, viewing angle and background consistent, avoiding a shadow or reflection on only one piece. Agree the direction when a material has an obviously directional texture. Actual retail lighting may differ from a viewing booth. Agree the controlled conditions used for the decision in advance and, if needed, make a separate observation on site. Do not call any one light the uniquely correct answer for every setting.
Approve the finished pair, not just the yarn
First compare small knitted samples made with the actual proposed yarn and structures and intended finishing, so obvious mismatches can be found early. Record composition, yarn or fabric supplier reference, colour, lot and finishing. If the cardigan and camisole share a colour name but use different yarns or lots, identify them separately. Even with the same yarn, construction and finishing can change the final appearance, so inspect finished garments too. Datacolor's textile colour management guide notes that texture, gloss and fibre composition can affect perceived colour; the actual garments still need physical review. A swatch answers an initial question about the submitted combination only and does not automatically cover other sizes, colours or future lots.
View both finished samples together in the intended combination and compare each separately with its approved standard. Check visible differences on the front, main wearing areas, shoulders and near seams; if one is worn over the other, compare the intended layered arrangement. Record whether the parties accepted “each item against its standard”, “the pair matches together”, or both. If either decision remains unapproved, keep it open; do not offset its failure with a pass on the other decision.
Put the decision scope on a record sheet
The following fields are suggestions for the project, not a laboratory method or a universal tolerance. If instrumental measurement is required, agree the equipment, conditions, formula, tolerance, specimen preparation and reporting responsibility with the actual measurement provider; combine that evidence with the agreed visual assessment. Neither an instrumental reading nor a visual result automatically represents all light sources, areas and batches.
| Decision | What to record | Approval question |
|---|---|---|
| Individual standards | Each piece's physical standard, identifier and version | Does each piece meet its own target? |
| Pair relationship | Garment IDs, side-by-side or layered arrangement, front or back | Do the pieces together meet the agreed appearance? |
| Light and observation | Primary and other light sources, background, direction and reviewer | Is the relationship still acceptable when the light changes? |
| Materials and finishing | Each piece's yarn or fabric, lot, construction and finishing | Do the samples represent the proposed production combination? |
| Results and changes | Each conclusion, open items, owner and change rules | Which sizes, colours or lots need another review? |
The public scope of AATCC EP9 describes general principles and a procedure for visually evaluating textile colour difference by comparison with a standard. The public summary is not the full method and does not set a pass value for this set. If the order requires that procedure, confirm the complete applicable method and version with the evaluator. Do not describe this project record sheet as a test already performed to that procedure.
What if only one decision passes?
Imagine a cream cardigan and camisole that look close under the primary source but differ noticeably under the agreed second source, even though each is still considered close to its individual standard. This is a hypothetical example, not a WTBF order or test result. Record the individual and pair conclusions separately. Until the pair decision is approved, do not call the whole set passed, and do not assert that metamerism is definitely the cause based only on the appearance.
The buyer and supplier can discuss adjusting the colour formulation, material or finishing, changing the objective from identical to coordinated, or holding affected production. Any choice may change handfeel, appearance, cost or time. Check feasibility and reapprove the affected finished pieces first; do not assume changing a yarn affects only colour. If the brand accepts a new coordinated difference, both parties should retain a new physical pair reference and its written scope as a version. When the supplier, lot, construction, dyeing or finishing changes, first decide whether the original approval covers it and repeat the comparison under the same conditions if needed. For reorder yarn and lot planning, see the dye-lot control guide.
Give WTBF an actionable colour brief
Through the WTBF inquiry page, provide the two styles and how they will be worn together, the yarn or fabric and construction direction for each, the physical colour reference, required primary and other light sources, sample sizes, quantities by style and colour, sales market and required warehouse arrival date. Say whether instrumental or independent testing is needed, who reviews the result and which conditions remain open. Confirm sampling, colour measurement, costs and timing for the project; do not treat a target date or desired match as an agreed commitment.