Ask a converter what the difference is between a kiss-cut and a through-cut and you get one answer: microns. Ask what happens when you get it wrong and you get a much longer answer, because the consequences range from labels that will not peel to a liner that fails in the press.
This article covers what each cutting mode actually does to a multi-layer web, how cut depth is set and verified on a rotary press, the two failure directions and their symptoms, and how cut depth interacts with waste-matrix stripping and line speed.
GB standard reference
- Standard
- GB/T 1299 (alloy tool steel) · GB/T 1220 (stainless)
- GB grades in this article
- W6Mo5Cr4V2 · Cr12Mo1V1 · Cr8Mo2SiV
- Also sold as
- M2 / SKH51 · SKD11 / D2 · DC53
- Hardness range
- HRC 58-63
1. What Each Mode Does to the Web
A pressure-sensitive label is a stack: facestock, adhesive, and a silicone-coated liner. The cutting edge has to do something different to each layer depending on the intended product.
| Mode | Facestock | Adhesive | Liner | Result |
|---|---|---|---|---|
| Kiss-cut | Severed | Severed | Intact | Labels stay on the liner, ready to dispense |
| Through-cut | Severed | Severed | Severed | Separate parts plus a waste matrix |
| Perforation | Partly severed | Partly severed | Varies | Part stays attached by defined bridges |
| Score | Compressed, not severed | Intact | Intact | Fold line for converting or consumer |
The entire difference between the first two rows is how far the edge travels into the third layer. In practice a kiss-cut penetrates the liner by a few hundredths of a millimetre — enough to guarantee the adhesive is fully severed, not enough to weaken the liner in tension.
Typical target penetration into the liner for a kiss-cut is 0.02-0.05 mm. Below that, adhesive strings survive and the label will not peel cleanly. Above it, the liner is scored and will break under web tension.
2. How Cut Depth Is Actually Set
On a rotary press, cut depth is not set by a depth stop. It is the result of the gap between the die's cutting edge and the anvil surface, which in turn comes from the die's outside diameter, the tooth height, and the pressure applied to the assembly. Three things set the working window:
- 1Die outside diameter and tooth height — these define where the edge physically sits, and they change every time the die is refaced, which is why the outside-diameter log matters
- 2Anvil condition — a worn, embossed or out-of-round anvil makes cut depth vary around the revolution, and no amount of die accuracy fixes it
- 3Applied pressure through the bearers or the cylinder loading — this is the only variable the operator controls on the day, and it is the one that drifts
2.1 Verifying depth without guessing
The reliable check is a penetration test on the actual material stack: cut a short length, lift the waste matrix, and inspect the liner with a magnifier or a low-power microscope. A correctly set kiss-cut leaves a visible but unbroken impression in the silicone coating. If the liner shows a continuous bright line with raised edges, the edge has cut into the liner and you are losing liner strength. If the matrix will not lift cleanly, you are still too shallow.
Raising pressure to fix an incomplete cut also increases side load on the teeth and accelerates edge wear. If the cut is incomplete at normal pressure, the real cause is usually a dull edge, an out-of-round anvil or the wrong bevel angle for the substrate — not insufficient force.
3. The Two Failure Directions and Their Symptoms
Cut depth errors only ever go one of two ways, and each has a distinct signature on the finished roll. Learning to read the symptom saves a lot of scrap.
| What you see | Likely cause | First action |
|---|---|---|
| Labels will not peel; adhesive strings at the edge | Too shallow — adhesive not fully severed | Check edge sharpness and bevel before adding pressure |
| Liner breaks under tension; parts detach in the press | Too deep — liner scored | Reduce pressure; check die OD against its log |
| Intermittent cut-through on part of the web | Anvil out of round, or die runout | Indicate the anvil and the die; check both |
| Cut quality varies across the web width | Uneven hardness or uneven pressure across the face | Check hardness report; verify bearer loading |
| Waste matrix tears instead of lifting cleanly | Geometry — inside radii too sharp, or insufficient web width | Review contour and matrix design, not just pressure |
4. Cut Depth and Matrix Stripping Are One System
After a kiss-cut, the coherent waste matrix is stripped away with defined tension and geometric guidance and wound up separately. If either the cut or the stripping parameters is wrong, the matrix will not release cleanly — and the two faults are easy to confuse.
- Webs between usable parts must be wide enough to carry the matrix tension without tearing
- Inside radii instead of sharp corners reduce notch cracks where the matrix starts to tear
- Long webs should run parallel to the pulling direction so the matrix does not neck down
- Deliberate hold points or micro-web features keep parts securely on the liner
- Peel angle and tension need to be stable — a dancer-controlled unwind is not a luxury on delicate contours
Static charge also matters. Die cutting generates it, and on light parts it lifts them off the liner before they reach the rewind. Ionisation and extraction are part of the cutting setup, not an afterthought bolted on afterwards.
5. Why Higher Line Speed Changes Everything
Cut depth is not the only variable in play when you increase speed. Higher web speed means more cutting cycles per minute, which raises edge temperature, and a hotter edge softens and wears faster. It also leaves less time for the substrate to recover from compression, so a bevel angle that cut cleanly at 80 m/min can start producing a fuzzy edge at 150 m/min.
This is precisely the point at which grade selection starts to matter more than die geometry. W6Mo5Cr4V2 will hold a fine edge at moderate speed but softens as edge temperature climbs; W6Mo5Cr4V2Co5 and W2Mo9Cr4VCo8 exist for exactly that regime. If your cut quality degrades only at high speed and only after the die has been running for a while, the problem is red hardness, not the contour.
Kiss-cut and cut depth: frequently asked questions
Kiss-cutting severs the facestock and adhesive while leaving the liner intact, so the parts remain on their carrier — this is how pressure-sensitive labels are supplied. Die-cutting in the broader sense may cut through every layer, producing separate parts. The mechanics are identical; only the penetration depth differs.
If you are troubleshooting a kiss-cut that has stopped behaving, send us the substrate stack, the liner type, the die's outside-diameter log and a photo of the cut edge. We can usually tell you whether the problem is the die, the anvil or the setup within a single exchange.
