Identify the unwind face
Place the roll as it will be supplied and photograph the leading label. Mark the top of the artwork, direction of travel and whether the label face is inside or outside the roll.
Label roll specification
Label roll core, web width and unwind guide
A wraparound labeller must accept the complete roll construction—not only the printed label. Record the core, web, liner, gap, roll diameter and winding direction before a machine trial or quotation.
- Core, web and finished-roll measurements
- Unwind and label-facing checks
- Production-roll sample checklist
Measure the complete roll
The label roll is a machine component.
Label length and width describe the printed piece, but the labeller also has to support, unwind, sense and tension the backing web. A production roll that differs from the trial roll can change tracking, sensor response and changeover time.
| Roll detail | What to record | Why the labeller needs it |
|---|---|---|
| Core inside diameter | Measure the clear internal diameter of the cardboard or plastic core. | The unwind mandrel or adaptor must support the roll concentrically without slipping. |
| Web width | Measure the backing liner from edge to edge, not only the label face. | Guides, peel plate and web path must clear the full liner width. |
| Maximum roll outside diameter | Measure a full production roll at its widest point and record roll weight where relevant. | Confirms physical clearance, unwind capacity and safe operator handling. |
| Label pitch and gap | Record the repeat from one label to the next and the clear gap between die-cut labels. | The sensor and feed control use this repeat to stop each label consistently. |
| Winding direction | State whether labels face in or out and which edge leads as the roll unwinds. | Determines artwork orientation, threading route and whether the label presents correctly at the peel edge. |
| Liner and label material | Identify paper, clear film, opaque film, metallic construction and liner colour or translucency. | Material contrast affects sensor choice and the liner affects web stiffness and tracking. |
| Splices and roll finish | Record whether production rolls contain joins, damaged edges, telescoping or inconsistent tension. | Irregular rolls can interrupt feeding or change the position of the web through the sensor. |
Measuring sequence
Record the roll in the order it travels through the machine.
Use a physical production roll wherever possible. Artwork drawings are useful, but they do not show liner stiffness, roll build or sensor contrast.
Measure core and web
Measure the clear core opening, liner width, label width, label length, gap and edge margins. Keep label and web measurements separate.
Check a full roll
Measure maximum outside diameter and inspect the roll edges. A short sample reel may pass a trial but not represent the clearance or handling of a production roll.
Confirm sensing
Test the actual label and backing liner together. Clear or low-contrast constructions may require a sensor selected for that web rather than a standard gap sensor.
Thread and track
Confirm that the web runs flat through guides, sensor and peel plate without edge contact, excessive tension or sideways movement.
Retain the reference
Keep the approved roll reference, photographs and setup record with the container format so future label orders can be checked against the tested construction.
Common specification errors
Small roll differences can create large setup changes.
Label width confused with web width
The liner is commonly wider than the die-cut label. Supplying only the label width can leave insufficient clearance at guides, sensor brackets or the peel plate.
Trial roll wound differently
If the production artwork arrives with a different leading edge or label-facing direction, the label may present upside down or require a different unwind arrangement.
Clear label tested on an easy liner
Sensor performance depends on the complete label-and-liner combination. Test the final construction, including varnish, print and any transparent window near the sensing path.
Outside diameter omitted
A machine may accept the web width but not the diameter or weight of the full roll. Record the largest production roll, not only a partly used sample.
Information to send with an enquiry
Send photographs of the roll from both sides, core inside diameter, maximum outside diameter, web width, label dimensions, gap, winding direction, material description and a production-condition sample roll. Pair this with the container measurements in the bottle diameter and label length guide, then use the label sensor guide when the label is clear, film or low contrast.
Quick enquiry
Send us your labelling requirement.
Include container diameter, label size, material, target output and whether the label is paper, film or transparent. Lancing can recommend a suitable semi-automatic, compact or automatic configuration.
Phone: 01494 623015
Email: sales@lancinguk.com