OK, there are Monotypes as well as Monoprints which are very often confused. They may look similar, but are different enough to make it important and actually pretty easy to understand. And then there are Ghosts.
A Monotype is a one of a kind piece printed using a smooth unmarked inked plate. Not reproducible. One of a kind. Unique. "Because there are no permanent marks on the plate, it is not possible to create multiples of the image." The same site explains the process of making a monotype: "To create a monotype the artist paints or rolls ink onto a blank plate. The image is created by manipulating ink with various tools (brushes, rags, stencils, etc.) Ink can be layered, color over color, and printed on the same paper in successive passes through the press. A Monoprint is a piece printed using an inked plate that has permanent marks on it such as scratches or gouges possibly in the form of a drawing, a pattern or abstract design of some type that are reproduced each time the plate is inked and printed. Because of these marks it is considered reproducible though still unique "due to the variations of how ink is manipulated in the image". According to WashingtonPrintmakers.com, monoprints "combine using some permanent marks on the plate along with variations of how ink is manipulated in the image. Each print is unique due to the various ways ink was manipulated from monoprint to monoprint."
A Plate I
A Ghost print
The Way Below Answer The piece at the top of the page is a Monoprint. If you look at the bottom blue area you can see undulating swirls. Those were permanently scratched into the plastic plate. Reproducible. It is also a ghost print. I put too thick an application of ink on the first printing which caused the first printing run to be so dark that it was almost unusable. It looked as though there might be enough ink left on the plate so I ran it through again using a bit more pressure on the roller and this is what I uncovered. Which I like.