Which signature goes on which surface?
A signature works together with the surface it sits on. What holds on glass may not hold on flexible packaging; the choice starts with the product.
For a signature to work, two things have to be true: it must be readable and it must last. Both depend on the surface. The same solution sits on a glass bottle for years and weakens on foil within months.
What the surface determines
- Adhesion: the bond the signature forms; porous and glossy surfaces do not behave alike.
- Background: the surface’s own luminescent behaviour can make reading harder.
- Wear: how the product is handled determines how long the signature survives.
- Downstream processes: lacquering, sterilisation and heat treatment can affect it.
None of these can be known without examining the product. That is why trials are run on samples before application: the signature is applied, read, then put through the processes the product will face and read again.
Reading on day one is not enough; the signature has to be readable for the life of the product.
Line constraints are part of the choice
Even when the surface suits, the application point has to fit the line speed and the stations that already exist. A signature that can be applied at the printing step is usually preferable to one that needs its own station — the line does not stop and the investment is small.
The choice is therefore not a purely technical decision: surface, line and reading scenario are weighed together. Leave one of the three out and the solution works on paper but not in the field.