Having read with interest the comments regarding single-fluid and waterless, I believe there is still a very long way to go with using a two-fluid system of ink and water.

While other areas of web press development, notably register, plate scanning and ink duct presetting, have seen increases in the degree of control and performance, damping has remained largely unchanged with the exception of spray damping.

It must surely now be possible by default to measure the exact amount of damping to apply. For example, it is possible to calculate from the image on a plate how to preset an ink fountain to give the correct density and coverage in zones across the plate e.g. if a plate requires 73% overall ink coverage then it must be that 27% requires no ink at all only damping. Whilst I accept that this is raw data and the correlation between ink and water is not linear at all press conditions, I believe an algorithm could be devised to ensure the correct damping in any printing situation. This would have to be augmented by an "on-press" device dynamically to measure in real time the damping film on a plate as is done with some on-press colour control systems.

To use this data effectively, as with an ink fountain, it has to be possible to apply the damping medium very accurately in zones i.e. typically with ink 32 over the width of a printing cylinder. One system that lends itself to this is spray damping. Spray nozzles are currently in use on many cold-set presses, but typically have only eight nozzles on a double-width press and can pulse at a maximum of around 60hz. With an increase in the number of nozzles, an increase to about 120hz and a closed loop system to measure continually the damping film on a plate, it will be possible dramatically to improve the performance of existing damping technology.

The advantages would be presetting of the damping profile, giving faster balance, less paper waste, less ink, faster makeready and true closed loop colour control, giving assured quality throughout the run. The system would be retrofittable, extending the life of older presses and making the most of new presses.

I do have some more advanced ideas too detailed to mention here. In the meantime I would appreciate any comments, especially from press manufacturers.

[时间：2003-08-18  作者：Bisenet  来源：Bisenet]