What Is a Lab Dip? Agree the Colour. Then Dye the Bulk.
A lab dip is how a brand and its mill agree on a colour before production. Here is what it means, how the process works, and how to approve lab dips in fewer rounds.
A lab dip is a small swatch of fabric or yarn that a mill or dye house dyes to match a brand's target colour, and sends back for approval before bulk fabric is dyed. It is how the brand and the supplier agree on a colour before any production fabric is made. The name comes from the dye laboratory, where the swatch is dipped in a test dye bath.
The same dye recipe looks different on cotton and on polyester, and the same swatch looks different under shop lighting and daylight, so colour has to be checked on a small piece before it is fixed on a large one.
Key takeaways
- A lab dip is a colour approval sample, dyed on the real material or one very close to it.
- The brand sends a colour standard. The mill dyes one or more options, and the brand approves, rejects or comments.
- Judge lab dips under agreed light sources against a physical standard, never on a screen.
- The approved lab dip becomes the reference for bulk dyeing and for matching trims.
- Keep a record of every submission per colour, per material and per supplier.
A small swatch now. No re-dyed bulk later.
Think of it as a colour contract between you and the mill, written in fabric. Colour is one of the first things a customer notices: a top and a bottom sold as a set must match, and a navy jacket must look the same navy in every store.
Bulk dyeing uses large quantities of fabric, so a wrong colour can mean re-dyed or rejected fabric and a late delivery. A small swatch that takes a few rounds is far cheaper.
Different materials also take dye differently. The shell fabric, rib trim, zip tape and sewing thread on one garment may come from different suppliers and different fibres. Each one needs to match the same approved colour.
Eight steps. From colour standard to bulk check.
- Set the colour standard. For each colourway, choose a physical swatch or a reference from a recognised colour system. This is the target every supplier matches.
- Send the request. Give the mill the colour standard, the base material (the actual fabric quality), the light sources you will judge under, and the date you need the dips.
- The mill dyes the options. Mills often send several variations of the same colour, labelled A, B and C, with small shifts in shade.
- Assess the dips. Compare each option with the standard in a light booth, under the agreed light sources.
- Approve, reject or comment. Be specific. "Slightly too red, make it a touch lighter" helps the mill more than "not right".
- Resubmit until approved. Each rejected round adds days to the calendar, so clear comments matter.
- Record the approval. Note which option was approved, on which material, by whom and when. Keep a cut of the approved dip as the reference.
- Check bulk against the dip. When bulk fabric is dyed, compare it with the approved lab dip before it is cut.
Six lab dip problems teams tell us about. And the fix for each.
The dip was approved on screen, so the colour in the hand was never checked.
Judge every dip against a physical standard. Screens and printouts do not show true colour.
The brand and the mill judged under different lighting. Two colours can match under one light and not under another. This is called metamerism, and it is a common reason for disputes.
Agree the light sources first, use a light booth (a cabinet with controlled light, such as daylight and typical store lighting), and check under more than one.
The answer is somewhere in an old email thread, so nobody is sure.
Record the approved option, material, approver and date on the product, and keep a cut of the dip.
The dip was approved on a sample fabric, but bulk uses a different quality, so the dye takes differently.
Ask for dips on the real base material, or one very close to it.
The shell fabric was matched, but the zip tape was never checked.
Match every dyed trim to the approved colour, not only the main fabric.
Dips waited in an inbox, so bulk fabric could not start and the delivery date slipped.
Give every dip an approver and a due date.
Follow one colour from standard to bulk
Imagine Rania, a product developer at a knitwear brand, approving a sage green for a new set:
- She sends the mill a physical standard, the base yarn and her two light sources.
- Options A, B and C arrive on the real yarn, and she checks them in the light booth next to the standard.
- B is close. Her comment reads: "B, slightly too yellow, make it a touch cooler."
- The resubmitted dip is approved, and she records it with her name, the date and a cut of the swatch.
- When bulk is dyed, the quality team checks it against that cut before cutting starts.
Judge the same way, every time
- Look at the same size and angle. Place the dip and the standard side by side, flat, at the same angle.
- Keep approvers consistent. Colour judgement varies between people, so the same small team should approve all dips for a season.
- Consider measuring colour. Some brands use a spectrophotometer, an instrument that measures colour as numbers, to reduce disagreement.
One of several colour approvals. Each has its own job.
- Lab dip. A solid colour on a dyed fabric or yarn.
- Strike-off. A test print of a printed design on the real fabric, used to check print colours, scale and placement.
- Yarn dip or knit-down. Used in knitwear to approve dyed yarn, sometimes knitted into a small panel.
- Trim approvals. Zips, buttons, thread and labels matched to the approved colour.
- Bulk shade approval. A swatch from the production dye lot, checked against the approved lab dip.
Lab dips happen in the development and testing stage, after colourways are set in the bill of materials and alongside garment samples such as proto and fit samples. Every dyed line in the BOM needs an approved colour. Our guides to the bill of materials in fashion and the types of samples in fashion show how they fit together.
When lab dips are tracked in email, the approved option, the comments and the dates end up in different threads. A PLM (product lifecycle management) system keeps them on the product record. If you are new to PLM, start with our guide to what PLM is.
How Polluxa helps
Polluxa PLM is product lifecycle management software for fashion, footwear, beauty, consumer goods and manufacturing brands. Our product lifecycle management software for consumer brands keeps samples, lab dips and approvals on one shared product record.
- Approvals no longer live in email threads. Get quotes and samples from suppliers and approve them, with samples and approvals tracked per style.
- Teams no longer work from different colour lists. Seasons, line plans and colourways sit together, so every team works from the same list.
- Dip comments no longer get lost in chat. With Vendor Management, discuss a dip on the quote, product or order itself. Each supplier sees only their part.
- Dips no longer sit in an inbox. Task and Workflow Management sends each approval to the right person with a due date.
- Nobody has to guess who approved what. Every change is recorded with who, what and when.
Start this week
- Agree two light sources with your main mill and write them into every lab dip request.
- For each open colour, write down which option was approved, on which material, by whom and when.
- Name one small group of approvers for all dips this season.
When you want to see this on your own styles and suppliers, book a demo.
Frequently asked questions
A lab dip is a small dyed swatch that a mill sends to a brand to approve a colour before bulk fabric is dyed. The name comes from the dye laboratory where the test swatch is dipped.
There is no fixed number. A simple colour on an easy fabric may be approved in the first round, while bright or very dark colours often take more. Clear comments and an agreed light source are the best ways to cut rounds.
A lab dip approves a solid dyed colour. A strike-off approves a printed design on fabric, including the print colours, scale and placement.
Usually the designer, a colour specialist or the product developer, sometimes with the quality team. Keeping the same small group of approvers for a season gives more consistent results.
Use the light sources agreed with the mill, normally a daylight source plus one that matches store lighting. Checking under more than one light helps you catch colours that match in one setting but not another.
