Scumming occurs on press when ------------ areas accept ink.

Sleeve is a plate used in ------------- printing process.

Before etching the surface of the gravure/cylinder which is not to be etched is covered with 

The common material used for offset plate graining 

The device that measures the image area percentage at selected area across the printing plate

In screen stencils making by 5-star film method, ----------------- is used as an oxidizing agent.