If you answered

"Not really a plate making process, but a printing process where the printer inks the plate to get tonal gradation."

You're wrong! Sorry


The continuous tone blended color in the upper
part of this print was applied with a printing
hand roller, rolling left-to-right, back and forth,
with a more saturated color blending into a
transparent ink at the middle.

Printers can achieve a continuous gradation in tone by several means, including careful wiping of the plate. Most gradation in tone, for a gradual, continuous change, is done with a roller or brayer and it's called "rainbow rolling" by many hand printers. In the trade it's called "split fountain", which means two or more colors are rolled out so that they blend together.

One example is the print at the left that in which I used a 4-inch lithographer's smooth hand roller on the copper etched plate. The image at the bottom, by the way, was Japanese-style woodcut, which is another way to get continuous tones.

Try another answer, please.

- GM