Colored Stretch Film: Using Colour as a Warehouse Coding System

Colored stretch film is pigmented polyethylene used to code loads by customer, route, shift or status without adding labels. The colour becomes part of the wrap, so it cannot fall off in transit and stays visible in racking. Black adds opacity for discreet loads, while light shades speed up stock identification. This guide helps buyers decide which colours to standardise, how pigment affects performance and what to specify before ordering.

1. What is colored stretch film and how is the colour added?

Colored stretch film is made by adding pigment masterbatch to polyethylene before extrusion, so colour runs through the film rather than sitting on the surface. Pigment is dispersed during melting and becomes part of the polymer matrix. That means it will not rub off on cartons or hands. Ask whether the pigment is suitable for contact with packaged food.

Pigment added before extrusion

Colour runs through the film

No coating to rub off

Check contact suitability

Dimension	Impact	Buyer action / evidence
Masterbatch	Consistent shade	Sample comparison
Dispersion	Even colour, no streaks	Roll inspection
Contact status	Retail and food use	Compliance declaration

2. How does colored stretch film support warehouse coding?

Colored stretch film supports coding because colour travels with the load and stays visible after stacking, unlike a label that can be hidden or detached. A scheme of one colour per customer group or dispatch day lets pickers identify pallets without scanning. The system only works if it is documented and enforced. Publish a colour chart at every wrapping station.

Colour stays on the load

Visible through racking

Fewer scanning steps

Needs a written chart

Dimension	Impact	Buyer action / evidence
Colour scheme	Faster identification	Documented chart
Station discipline	Scheme integrity	Station audit
Racking visibility	Picking speed	Aisle observation

3. Which colored stretch film colours suit which purposes?

Colored stretch film colours should be assigned by function rather than preference: black for opaque or security loads, red for priority or hold, blue and green for route groups, and clear where label reading matters. Too many colours create confusion, so limit the palette to four or five. Print the mapping beside the wrapper.

Black hides contents

Red signals priority or hold

Blue and green split routes

Limit the palette

Dimension	Impact	Buyer action / evidence
Opacity	Load concealment	Light transmission check
Contrast	Reading at distance	Aisle visibility test
Colour count	Operator confusion	Simplified chart

4. How does colored stretch film affect film strength?

Colored stretch film usually performs slightly below natural film at the same gauge because pigment particles interrupt the polymer structure and reduce stretch headroom. The effect is small with well-dispersed masterbatch but noticeable with heavy pigment loading. For heavy or export loads, specify a grade tested in that colour. Do not assume clear-film data applies.

Pigment can cut elongation slightly

Heavy loading has more effect

Strength varies by colour

Test the exact shade

Dimension	Impact	Buyer action / evidence
Pigment load	Elongation loss	Grade test data
Dispersion quality	Weak points	Film inspection
Gauge compensation	Restored strength	Adjusted specification

5. Where does colored stretch film fit in export and security work?

Colored stretch film fits export and security work because an opaque wrap conceals carton markings and makes tampering obvious, since any cut or patch breaks the colour continuity. Black film is common for high-value electronics and branded goods. Red or orange often flags inspection or customs holds. Confirm the colour resists sunlight before a long sea journey.

Opaque wrap conceals contents

Cuts are easy to spot

Colour flags inspections

Check lightfastness for export

Dimension	Impact	Buyer action / evidence
Opacity	Content privacy	Opacity sample check
Tamper visibility	Security assurance	Cut test on sample
Lightfastness	Colour fading	UV exposure data

6. How does colored stretch film affect recycling?

Colored stretch film affects recycling because dark pigments, especially carbon black, are hard for optical sorters to detect, so coloured film often drops into lower-value streams. If you run a closed-loop programme, keep colours separate or standardise on detectable shades. Ask your recycler which colours they accept. Design the scheme with end of life in mind.

Carbon black blocks optical sorting

Coloured film lowers recyclate value

Segregate colours if recycling

Ask the recycler first

Dimension	Impact	Buyer action / evidence
Pigment type	Sorting feasibility	Recycler confirmation
Segregation	Stream purity	Colour-separated bins
Recyclate value	Programme economics	Buyer agreement

7. How should a buyer choose a colored stretch film scheme?

Buyers should choose a colored stretch film scheme by listing the decisions operators currently make with labels, then assigning colour only where it removes a step. Keep the palette small, pick high-contrast shades and test visibility under your own lighting. Involve warehouse supervisors, who know where confusion happens. Pilot on one line before company-wide rollout.

List label-based decisions first

Assign colour only where useful

Test under real lighting

Pilot on one line

Dimension	Impact	Buyer action / evidence
Decision list	Scheme scope	Process mapping
Lighting	Colour legibility	On-site test
Pilot result	Rollout confidence	One-line trial data

8. What should a buyer request before ordering colored stretch film?

Before ordering colored stretch film, buyers should request film samples in the actual grade, a specification listing gauge, width and length, and confirmation of pigment dispersion quality. Check that the shade matches across a full roll and between batches, since colour drift is the commonest complaint. Approve a physical reference sample and keep it on file.

Request film samples, not colour cards

Check shade across the roll

Confirm batch-to-batch control

Keep an approved sample

Dimension	Impact	Buyer action / evidence
Sample medium	True colour match	Film sample approval
Shade consistency	Brand discipline	Batch comparison
Reference sample	Dispute resolution	Signed standard

Frequently Asked Questions

Q1. Does colored stretch film cost more than clear film?

Colored film usually costs slightly more than clear film at the same gauge because of pigment and colour control. The premium is small against the labour saved by faster identification.

Q2. Can colored stretch film be recycled?

It can be recycled, but dark pigments may not be detected by automatic sorting equipment. Segregate colours or confirm acceptance with your recycler before building a programme.

Q3. Is black stretch film strong enough for heavy loads?

Black film can be strong enough if the grade is engineered for it, but heavy pigment loading can reduce elongation. Specify a grade tested in black rather than assuming clear-film data.

Q4. Will the colour rub off on my cartons?

Colour is dispersed inside the polymer, so it does not rub off like a printed coating. Poorly dispersed masterbatch can leave streaks, which is why you should inspect a full roll.

Q5. Can RX Packaging supply colour-coded film alongside standard grades?

RX Packaging produces cast and blown stretch film and can discuss colour-coded supply against your coding scheme, so request film samples in the shades you plan to standardise.