Increase in Tone Value |
 |
An increase in tone values means a gain in the halftone dot of the print compared with the original (film, printing plate). In order to establish an increase in tone value, a full tone field combined with a defined grid is needed.
The problem of an increase in tone value may arise during the preparation of the printing form. While an increase in tone value in a printing press cannot be entirely avoided, it should never be allowed to exceed a certain point.
An increase in tone value depends on type of ink, ink quantity, the temperature in the inking system, the surface of the printing stock, release from the blanket, the dampening solution, and the quantity of dampening solution employed.
| |
Remedy:
- Print with a familiar ink series, without additives if possible, within the tolerance levels of your own standards of density
- An increase in tone value (approx. 2%) must be taken into consideration during black and white printing
- Employ appropriate black and white inks
- Set the inking system between 27°C and 30°C (80°F and 86°F)
- Avoid changing the printing stock during the print run
- Clamping between the plate and the blanket should be set between 0.1 mm and max. 0.13 mm (0.004 in and 0.051 in)
- Pressing between the blanket and the counterpressure should be set to reflect the printing stock surface; avoid setting compression too high
- A fixed type of blanket should be used in the pressroom (standardisation)
- Only use certified cleansing solutions when washing
- Wash new blankets with water after mounting in order to remove the talcum
- Newly stretched blankets must be re-stretched
- Run the quantity of dampening solution slightly over the smear limit, and precisely maintain the balance of ink and dampening solution
- Optically test the three quarter tones with a line tester
|
|
|
|
|
|
|
|
|
 |
|
POLAR Cutting Tips
This series of POLAR Cutting Tips helps to increase the machine performance and its efficiency.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|