Color Proofing Bags: Pantone to Actual Fabric Dyeing

How does a Pantone reference become actual dyed fabric on a handbag? It does not transfer directly. A Pantone TCX code names a target; the colour on the bag is produced by a dye recipe that has to be built, dipped, measured and approved. The practical route is three lab dips, one physical swatch approved under a defined light source, and a Delta E tolerance of 2.0 or better against that swatch — anything looser shows as a visible mismatch once panels from different lots meet on one body. Budget 2-4 working days per dip round, and approve cloth, lining, thread and plated hardware as four separate matches, because a bag is four colours wearing together rather than one.

Colour proofing parameters we work to

What a Pantone Code Is and What It Is Not

A Pantone reference is a naming system, not a recipe. TCX codes are printed on cotton and describe a colour as the eye should receive it; they say nothing about which dyestuffs, at what concentration, on which substrate, will land there. That is why the same TCX code arrives as four visibly different swatches when it is sent to a leather finisher, a polyester coater, a lining weaver and a plating bath. The code is the destination, and each supplier writes its own route.

Why Does the Same Code Look Different on Leather and on Fabric?

Because dye uptake is a property of the material, not of the target. Full-grain leather absorbs pigment into a fibre structure that varies hide to hide, so a recipe is a starting point that gets corrected per lot. Coated polyester sits on the surface instead, which means the coating thickness and the emboss grain change the reading. A 0.12 mm PU coating over 600D polyester will read darker and glossier than the same pigment on 900D with a matte topcoat, even when both measure close to the same code.

• Substrate. Leather, PU-coated polyester, nylon, canvas and coated webbing each take colour differently and each needs its own recipe.
• Finish. Matte, semi-gloss, waxed and embossed finishes shift the same pigment by a whole step on a grey scale.
• Thickness. A 1.2 mm split reads differently from a 1.4 mm full grain of the same shade, because backing and density change reflectance.
• Viewing. Without a defined light source the same swatch reads green under store fluorescent and warm under tungsten, which is the source of most approval arguments.

The practical consequence is that a colour brief should never be a single code. It should be one code per component: body, lining, thread, binding, zip tape and plated hardware. That is also how the tech pack should be built, because a colour that is only specified for the body leaves the lining to be chosen for you.

The Lab Dip Sequence, Checkable Step by Step

A lab dip is a small dyed sample produced on the actual production substrate, submitted for approval before any bulk dyeing begins. Three dips per colourway is the working norm: one on recipe, one corrected, one confirmation. Each round costs 2-4 working days, which is why colour is the single most common reason a sampling window of 6-10 working days stretches.

1. Recipe build. The dyer converts the TCX code into a formula for that substrate and finish, usually within one working day.
2. First dip. A 10 cm by 15 cm swatch is dyed and dried. This first attempt is expected to be off; its job is to show by how much and in which direction.
3. Instrument reading. The swatch is measured against the reference with a spectrophotometer and the Delta E value is recorded, not guessed.
4. Second dip. The recipe is corrected from the reading. Most colourways land inside tolerance on this round.
5. Third dip and retain. A confirmation dip is produced, cut in three, and one piece is retained as the physical standard for bulk.

Where a colourway is a brand shade repeated across seasons, the retained swatch is the asset that matters. It turns the second order into a comparison against a physical object rather than a fresh search, and it removes a dip round from the calendar. A sampling timeline built around approved artwork shows where those days sit in the wider window.

Measuring the Match: Delta E and the Light Booth

Delta E is a single number for the distance between two colours in a defined colour space; the computation method is set out in ASTM D2244. Below about 1.0 the difference is invisible to most observers; at 2.0 it is a close commercial match; beyond 3.0 most people notice it on adjacent panels. Writing Delta E 2.0 or better into the specification converts colour approval from taste into a threshold.

• Name the primary source. D65, the daylight standard, is where the approval decision is made.
• Name two check sources. TL84 for store fluorescent and F11 for warm retail lighting, to expose metamerism before the goods reach a shop floor.
• Name the geometry. Measurement at a defined angle and aperture, so the same reading can be reproduced next season.
• Name the instrument tolerance. Agree in advance whether the instrument or the eye has the final say when they disagree.

Metamerism is the failure that instruments miss and customers do not. Two materials can measure identical under D65 and diverge visibly under TL84 because their reflectance curves differ. That is the reason a check source is mandatory rather than optional, and the reason a body and its lining should always be approved side by side rather than in separate envelopes.

Where Colour Goes Wrong on Bags

Colour complaints on finished bags cluster in a small number of places, and nearly all of them are predictable from the specification. Knowing where the failures sit is cheaper than discovering them at inspection, because a recut is measured in weeks and a redye is measured in a lost season.

Notice that three of the four are document problems. Two dye lots in one bag is a cutting instruction; a lining approved alone is a procedure gap; a brightener issue is a packaging specification. Only the rubbing failure is really about the dye, and it is caught by one test that costs almost nothing to run.

Trims, Thread and Hardware Are Part of the Match

A bag is judged as an assembly, and the eye reads the smallest contrast first. Thread is the classic offender: specified as matching, delivered as a shade lighter, and then visible along every seam of a 34 cm tote panel. Binding, zip tape, edge paint and plated hardware each need their own reference, and each is a separate purchase with its own lot.

• Thread. Tex 40 polyester or bonded nylon, specified to a code and approved against the body rather than against a shade card.
• Edge paint. A liquid applied in two or three passes; it dries darker, so the wet sample is not the finished colour.
• Zip tape and slider. Tape, chain and puller can arrive from three sources in three whites and three golds.
• Plated hardware. Zinc alloy with a stated plating thickness in microns; gold tones vary by bath, so a physical sample is required.

Hardware in particular should be approved as a physical part on a physical body. A brass tone that reads correct against a swatch card can read green against a tan leather, which is a pairing problem rather than a plating defect. Where hardware carries a plated finish, a 24-hour salt spray check to ASTM B117 is the durability companion to the colour match.

Colour Fastness: Whether the Match Survives

Matching a swatch on day one is only half the requirement. Fastness testing asks whether the colour stays where it was put: rubbing to ISO 105-X12, light exposure to ISO 105-B02, and perspiration and water where the bag will be carried against clothing. Grade 4-5 dry and grade 4 wet on the grey scale is the commercial expectation for a body material; lining, which sits against lighter garments, should be held to the same grade rather than excused.

• Rubbing, ISO 105-X12. Ten cycles dry and ten wet, rated on the grey scale, catching pigment that sits on the surface.
• Light, ISO 105-B02. 40 hours xenon arc as a screening level for a bag that will sit in a window or a shop display.
• Perspiration. Relevant for strap contact on light clothing, and a common omission in briefs written by colour rather than by use.
• Chemistry. REACH Annex XVII restricts certain azo dyes and sets chromium VI limits on leather; California Proposition 65 adds a separate warning analysis for coated trim.

Where leather is sourced through a tannery with Leather Working Group traceability, ask for the tannery reference alongside the test report. It shortens the compliance conversation with a retailer later, and it is the difference between a test result and a chain of custody. The same applies to a GRS transaction certificate where a recycled polyester or nylon is specified.

The Swatch Approval Checklist

Approval is a decision with a document attached, and the checklist below is what that document should record. Working through it takes minutes at approval stage and saves a re-sort at inspection, which is the expensive place to discover that nobody wrote the tolerance down.

1. Is there a physical swatch? A screen approval is not an approval; pixels are not a dye lot.
2. Is the substrate correct? Approve on the production material, at production thickness, with the production finish.
3. Is Delta E recorded? Write the measured value against the reference, not just an impression.
4. Were two light sources used? D65 for the decision, TL84 or F11 for the metamerism check.
5. Are trims approved together? Thread, binding, zip tape and hardware on the same card as the body.
6. Is fastness tested? ISO 105-X12 grade 4-5 dry and grade 4 wet, reported before approval rather than after.
7. Is a retain cut? Three pieces, one retained by you, one by the production partner, one for the inspector.
8. Is the lot number recorded? The dye lot that produced the approved swatch is the lot bulk must match.

The last two items are the ones that make a second order cheap. A retained swatch plus a recorded lot number means the repeat starts from a standard; without them the repeat starts from a search, and the search costs a dip round and 2-4 working days.

What to Send With a Colour Brief

A colour brief that arrives as one code and a mood image comes back as three dips of guesswork. A brief that arrives with a substrate, a finish, a tolerance and a physical reference comes back as a match. The difference is ten minutes of writing.

• One Pantone TCX code per component, body, lining, thread, binding, tape and hardware tone.
• Material and finish specification, including thickness in millimetres and whether the topcoat is matte or gloss.
• A physical reference if one exists, even a competitor bag or a fabric cutting, which beats a code alone.
• The tolerance you will accept, written as a Delta E value rather than as close or good.
• The end use, because a bag carried against white linen needs a perspiration test and a shop display needs light fastness.

Send the brief before the sampling and approval process starts rather than alongside the first sample request. Colour is the longest pole in the sampling tent, and it is the only one that can be started in parallel with pattern work.

Holding the Colour Through Bulk

Approval is not the end of colour control; it is the reference point for it. In bulk, the controls are a single dye lot per colourway, a retained standard on the cutting table, and a pre-shipment inspection at AQL 2.5 under ISO 2859-1 that treats shade deviation as a defect class rather than as a matter of opinion. Where a run exceeds one lot, cartons should be marked by lot so a retailer can keep shades together on a shelf.

Two habits do most of the work. First, freeze the specification at deposit: a colour change after the dye lot is ordered is a new lot, not a small favour. Second, book inspection before the goods are packed rather than after, because a shade issue found at the table can be sorted and one found in a warehouse cannot. Both are covered in more detail in the guide to approving a sample without surprises later.

Dye Lot Minimums: What One Colourway Commits

A colourway is a purchase before it is a decision, and the purchase has a minimum set by the dyer rather than by the bag programme. Leather is traded by the hide and by the lot, fabric by the metre and by the piece, and both have floors that a 500-piece order can either clear comfortably or trip over. Knowing the floor is what stops a fourth colourway from being added on the assumption that it is only a code.

The Cost and Time of a Re-Dip

Every extra dip round is a line on the invoice and a hole in the calendar, and both are small individually and large in aggregate. A dip costs very little in cash and two to four working days in time, which inside a 35-50 day bulk window is the more expensive of the two. Counting the rounds a colourway has consumed is the fastest way to see whether the brief or the dyehouse is the problem.

• One dip round is 2-4 working days and a charge of USD 15-40 on fabric, or USD 40-90 where a hide has to be cut into.
• Three rounds is the working norm for a new colourway: recipe, correction, confirmation. A fourth round almost always means the physical reference was missing.
• A re-dip on bulk material costs differently. Re-dyeing a booked lot of 30-40 hides runs USD 250-600 and 8-14 days, which can move a shipping date.
• Approve against a physical swatch, never a screen. Every additional approval made on a photograph adds one round with roughly 80 per cent probability.

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