Ablation is a general term that refers to the removal of material from the surface of an object by vaporization, chipping, or any other erosive processes. In prepress, ablation is a technology that is used in some output systems:

  • Ablation can be used in computer-to-plate and direct-to-press systems to image plates by vaporizing or blasting away a part of the emulsion, typically with a thermal laser. A number of chemical-free or process-free CtP plates rely on this technology.
    • In some ablation based systems the plate emulsion that is ablated is washed from the surface of the plate before it is used for printing at the press. This can be done in a clean-out unit that also gums the plate.
    • With controlled ablation plates it is the fountain solution at the press that loosens the debris from the plate.
  • In the past, some ablation based CtP systems used ablation to also generate proofs on the same device. I don’t think any of the current systems on the market still do this.
  • Ablation can also be an unwanted side effect of the use of laser technology. With all thermal CtP systems, some unwanted ablation occurs. In many system a series of filters minimizes the health risk for operators.