Two different properties are often lumped together as “stickiness”. Tack is how firmly a label grabs the moment it touches the surface. Holding power — shear adhesion — is how long that bond survives under a constant load. A label can be high in one and poor in the other, which is why we test them separately.
Holding power (shear adhesion)
| Item | Condition |
|---|---|
| Reference standard | FINAT FTM 8 |
| Bonded area | 25 × 25 mm on polished stainless steel |
| Load | 1,000 g, vertical |
| Dwell before loading | 20 min |
| Result | Time to failure, in hours; failure mode recorded (adhesive / cohesive) |
Tack (loop tack)
| Item | Condition |
|---|---|
| Reference standard | FINAT FTM 9 |
| Specimen | 25 mm wide loop, no applied pressure |
| Separation speed | 300 mm/min |
| Result | Peak force, N/25 mm |
Why the trade-off matters
Adhesives built for high initial tack tend to be soft, and soft adhesives creep under sustained load — they score well on tack and badly on shear. Firmer adhesives hold for hundreds of hours but need pressure and dwell time to reach full bond. If your label is applied cold, to a curved surface, or to a container that is filled and stacked immediately, tell us which of the two failures you can least afford.
When to ask for this test
- Labels on drums, pails and jerrycans that are stacked or strapped
- Small-diameter bottles and tubes where edge lift is the usual complaint
- Low-energy surfaces — PE, PP, powder-coated metal
- Any change of adhesive on a construction that already works
Related: Label Laboratory · High temperature resistance · Low temperature resistance