A dark handle can look correct beside a pale bag body and still leave an unanswered question: what happens when that coloured surface rubs against something else? Shade approval and colour-transfer assessment are different tasks. A signed colour swatch does not settle both.
A cotton tote bag rubbing colourfastness assessment concerns the coloured fabric, handles or print that may touch clothing during use. Tell the supplier or laboratory which surfaces and conditions matter. The methods below explain how to frame that request, not whether a Gahumi material has passed.
Ask about transfer, not simply “colour quality”
Rubbing colourfastness concerns colour coming off a surface and staining another material through rubbing. It is not the same as deciding whether the navy is close enough to the approved navy, or whether the bag changes after washing.
ISO’s public summary of ISO 105-X12 describes rubbing assessment with dry and wet cloths. AATCC also lists a TM8 crockmeter method for colour transfer by rubbing. These are method references to discuss with the testing service, not interchangeable pass certificates.
Whether cotton tote bags need dry rubbing tests, wet rubbing tests or both depends on the agreed use and purchasing requirements. The buyer’s technical team and laboratory should confirm the scope. A dry result cannot stand in for a requested wet result, and there is no pass grade in this article that applies to every bag sold in Europe.
List the actual surfaces
A two-tone bag may combine a pale body, dark handles, a darker base and a printed graphic. Give each relevant surface its own reference. Ask the laboratory how it can assess narrow straps, seams or small printed areas before sending a sample.
- Name the style, component, fabric or decoration reference and colour.
- Identify which face or printed area is intended for assessment.
- Record the sample date and batch information available.
- State whether the material is in its original state or has received an agreed treatment.
- Explain what the component is expected to contact in normal use.
Ask how much material the service needs and whether finished bags, loose components or both should be supplied. Do not cut up the only approved sample without agreeing which record will remain as the production reference.
Agree the method before discussing the grade
A colourfastness test request needs the agreed method and edition, component scope, dry or wet conditions, any pretreatment, report format and acceptance criteria. Have the laboratory resolve technical details that cannot be inferred from a buyer’s sketch.
If a requirement already comes from your brand’s purchasing standard, provide that actual document. Ask the supplier and testing service to confirm whether it applies to the proposed materials. A method number copied from another retailer’s specification is not a complete agreement.
Do not describe a quick rub with a damp cloth as an ISO or AATCC test. An informal observation can justify further investigation, but it lacks the controlled procedure and reporting required to claim the named method.
Read the report against its sample
Check the sample description before the result. Does it identify the intended handle, print or base fabric? Does the colour and batch reference match what was supplied? If the report describes a loose fabric swatch, do not relabel it as a test of every finished bag.
Keep dry and wet results distinct, together with any stated limitations. Refer questions about method suitability or unusual outcomes back to the laboratory. The buyer should agree the decision process with the supplier rather than translating one grade into an unsupported “never fades” claim.
The separate fabric shade guide covers appearance matching. Use both records where both issues matter; one does not replace the other.
Review the evidence when materials change
For a cotton or canvas bag intended for regular use, keeping its appearance and avoiding unwanted colour transfer are worthwhile design objectives. Choose the actual dyed cloth and decoration with those uses in mind, rather than adding an unnecessary covering layer to conceal an unresolved material issue. If a handle colour, fabric source, ink system or processing route changes, check whether the existing evidence still applies. A report on one navy material does not establish results for another.
Keep care evaluation separate but connected. Where testing is required after an agreed cleaning process, identify that process and the sample state explicitly. The finished-bag care review provides the wider record without promising a particular wash performance.
Send Gahumi your component list, intended use and any actual test specification, with quantity and delivery country. Ask what materials, samples and testing arrangements can be confirmed for the enquiry before approving a performance claim.
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Prefer email? Send the component requirements to gzgahumibag@gmail.com.