The press consists of a heavy steel bad-plate turning between two rollers, the lower being larger and generally hollow, with some means of turning the upper roller. The plate is heated while an adhesive ink is forced into its grooves and indentations, the excel ink being removed with a gauze pad or with the palm of the hand. It is then laid face up upon the press with a moistened sheet laid upon it, the whole being covered with several layers of wooden blankets.
When the bed with its charge passes between the rollers, the pressure causes blankets and damp paper to take a cast from the ink plated mold. Printing from intaglio in color has been done traditionally by successive printings of different plates on the same sheet.
In one method holes are drilled through the registration. Two or four needles passed through the paper resting in the holes in the plate being printed then ensure the position of the sheet on the plate.
The earliest practitioners of engraving in the West, the goldsmiths, sometimes made molten sulphur casts from their work or took pressings in clay from it.
The earliest prints know from intaglio plates were made by goldsmiths and in an age in which anonymity of the builders of the Gothic cathedrals was normal, their works are distinguished only by marks or monograms which are common in logo design.
Another method of plate making has been in existence from the thirteenth century. The armorers had the practice of covering steel with beeswax and drawing through the wax with a point. The trace was then eaten into the metal with acid, sometimes by packing bags of salt on it and soaking them with vinegar.
As the first etchings were made on iron, it suggest that the craft was learnt from the armorers.