retroussage

Retroussage, re-trōō-sazh′, n. a method of producing effective tones in the printing of etchings by skilful treatment of the ink in certain parts.

To produce the proper effect the retroussage must be general; because, if the rag passes over one passage only, and not over the others, or, if it is brought into play only on the dark parts, and not in the lights, there will be discordance of tone, and consequently want of harmony.

In the present case, therefore, retroussage would be unsatisfactory, because the work on your plate, while it is broadly treated in some parts, is so close in others that there is no room left between the furrows.

It follows that there is no place for the ink, drawn out of the lines, to spread on; the result would be a muddy tint,—one of those overcharged impressions which bring criticism upon the printer, because he has applied retroussage to a plate which did not need it.

This method of wiping, which leaves on the surface of the plate a tint of more or less depth, must not be confounded with retroussage.