Custom-shaped labels and dies: half-cut vs full-cut, matrix waste, spacing and small batches

1. Three kinds of die, three different jobs

Most roll-label plants run the middle option. Changeovers are quick and a worn blade can be replaced on its own; the trade-off is that die and cylinder are a matched pair — move the same die to a different cylinder and the cutting depth changes. That is the technical reason a die that worked at one supplier can fail at another.

The mechanism is simple: the cutting cylinder is pressed against the anvil cylinder by pneumatic or mechanical pressure, and the blade cuts the face material. The liner is compressible like any other material — over-pressure thins it and the blade breaks through. So half-cut is not really about how sharp the blade is; it is about liner calliper tolerance. A few microns of variation across a batch, pressure set at the limit, and you get sections that cut through next to sections that do not. That is why a new liner batch means re-setting pressure.

2. Half-cut or full-cut: decided by how the label is applied

One line: applicator means half-cut; hand-peel means full-cut. Doing both for one product — rolls for the factory line, loose labels for store touch-ups — is perfectly normal, but it means two dies and two die charges, so price them separately.

3. The die charge: what it buys, who owns it, when it must be re-made

• Reusable when shape, size and layout are unchanged. New copy, new colours, a new barcode — that is a plate change, not a die change.
• New die needed when the outline changes, the size changes, the way several labels are nested on the sheet changes, the die type changes (flatbed to rotary), or the previous supplier will not release the die.
• Settle ownership up front: whether the die is yours after you pay for it, whether you can take it to another supplier, and what happens to it if you move. Put those three sentences in the quotation or order confirmation and the argument never happens.
• Dies wear. The signs are frayed edges, a whitened cut line where the face material is torn rather than cut, patches that stay uncut, and a matrix that snaps. Flexible dies allow a blade change; a solid rotary die has to be re-made.

4. Six hard constraints for custom shapes

1. Round the corners. Right angles and sharp points concentrate stress on the blade and tear when peeled. Use a radius of 1.5mm or more.
2. Keep detail at 1mm or above. Thin necks and fine points can be cut but not cut reliably, and the matrix tends to pull them away.
3. Notches need width. Waste has to escape through a notch; below about 3mm it jams.
4. Extend print past the cut line. Dies have manufacturing and registration tolerance, so backgrounds and images flush with the edge show white when the cut drifts. Carry print about 2mm beyond the die line.
5. Leave nicks. Tiny uncut bridges hold the label in the matrix during half-cut and keep the label from flying off. Place them away from key artwork and barcodes.
6. Keep codes away from the edge. Labels stretch on curved bottles and the code nearest the edge distorts first. Allow at least 3mm, more on small diameters.

5. Spacing and matrix: where the unit price is really decided

How many labels fit on a sheet depends on label size plus gap. Rectangles nest tightly; irregular shapes need wider gaps so the waste web stays connected, and a sheet that would take ten rectangles may take six or seven of the custom shape. Yield drops, price rises — on every label, not once.

When the matrix is stripped matters more than people expect. If waste is not pulled away immediately after cutting, adhesive recovers at the cut line; the next cut frays, and sometimes lifts the face material. That is why the same die drawing can produce a clean edge at one plant and a ragged one at another — it is the stripping and tension settings, not the blade.

6. Making tooling pay on small Hong Kong, Macau and Southeast Asian runs

• Start with a standard shape. Circles, rounded rectangles and ovals exist as stock dies; small runs can skip the die charge entirely. Reserve custom dies for the SKUs where the brand genuinely needs the outline.
• Several designs, one die. Nest two or three artworks inside the same outline on one sheet: one print pass, one cut, delivered as separate rolls. Common during a test launch, and it spreads both the die charge and the set-up.
• Very small quantities: digital plus a cutting plotter. Tens to a few hundred pieces, custom shape, needed now — cut directly from digital print with no die at all. Higher unit price, zero tooling, no minimum.
• Record the die number. Quoting a repeat order by die number saves the supplier from hunting and re-testing the tool, which shortens both quote and lead time — and it is what you need if you ever ask another plant to take the job over.

7. Seven things to send with an enquiry

1. Outline drawing, vector (AI/PDF/EPS) with dimensions — or the existing die number or die drawing.
2. Finished size and quantity, split by version, and whether you need rolls or loose labels.
3. Half-cut or full-cut; for rolls, unwind direction, core diameter, labels per roll and whether an eye-mark is required.
4. Face material and adhesive (paper, PET, PP; permanent, removable, freezer), and what it will be applied to.
5. Artwork and colour count — spot colours, foil, spot UV.
6. Destination market and the labelling requirements that apply (food contact, ingredients, barcodes).
7. Required delivery date, and whether partial shipments are acceptable.

Send all seven at once and the quotation comes back right the first time; leave one out and it usually takes two or three rounds.

Related reading: Specifying roll labels, Cold-chain label materials, Export carton marking, Barcode print quality, Overstickers for Hong Kong retail, Label applicator compatibility and roll specification.