When choosing laminated paper or board for a packaging product material, whether it is a bag or a box, several significant facts need to be taken into consideration. The behaviour of the laminated printed sheet is related to the appearance of your luxury packaging, that is why it is important to get acquainted with the various factors which determine the outcome of applying laminate over ink.
- the colours of the printed sheet may feature different shades compared to the non-laminated copy.
The laminate that is applied directly over the printed sheet causes a variation in the path of the light hitting the sheet: first directly on the printed sheet and after lamination, through the plastic film. Since the colour perception is affected by the light’s path, this phenomenon must be taken into account.The colour change of the ink in the light is amplified by the plastic film.
- the contrast and intensity of colours may be decreased.
A factor that helps us understand the differences between a laminated printed sheet and a non-laminated one is the dot gain value. This value increases significantly with lamination. It is obvious that the dot gain is not physical but instead optical, i.e. due to the film layer that amplifies the visual perception of the dot dimensions. It is as if the film acts as a magnifying glass. Due to this effect, if the dot gain increases, as a result the print contrast decreases.
- The laminate may be detached from the sheet along the creases of a laminated paper product.
It is crucial that the inks are completely dry both on the surface and internally; otherwise the lamination process may determine an undesired reaction, resulting in anomalies that affect the plastic film, making the film detach and making the printed sheet non-compliant. This most often happens when the sheets are fully printed in solid colour. That is why we need longer production time for products with a 100% colour background. Another solution is the use of IP film laminate for wet inks.