Steel Engraving
Like copper engraving this method also uses an intaglio technique.
Developed at the beginning of the 19th century, initially for use in
producing issues of bank notes, by about 1830 harder steel plates were
being used to produce finely rendered engravings using closely cross
hatched lines. The technique was the same as that for copper engraving
but the lines tended to be shallower therefore producing lighter tones
on the printed paper.
Plates were often engraved in conjunction with other forms of line engraving
to produce differing tonal qualities. Although permitting greater numbers
of impressions to be taken form a plate than allowed by copper engraving.
The sheer hardness of the steel however made the work rather arduous
until the discovery of steel facing; the covering of an engraved copper
plate with a thin, replaceable layer of iron by electroplating in the
1850s, greatly facilitated the work of the engraver.