Copying an existing painting and selling it as an original is the most common type of painting forgery, as it is relatively easy to do and can be difficult to detect.

A forgery is a painting that is created to deceive buyers into thinking it is an original work of art. It is illegal to create or sell a forgery.

X-ray analysis, infrared reflectography, pigment analysis, and dendrochronology are all techniques used to detect painting forgeries. These techniques can help to identify the age, materials, and techniques used to create a painting, which can help to determine if it is an original or a forgery.

Han van Meegeren is considered to be one of the most notorious art forgers of all time. He was a Dutch artist who created a number of fake paintings in the style of Johannes Vermeer, which he sold to museums and collectors for large sums of money.

The International Foundation for Art Research (IFAR) is a non-profit organization that is dedicated to fighting art forgery. IFAR provides a variety of services to help museums, collectors, and law enforcement agencies identify and prevent art forgery.

Craquelure is the technique used to create a fake patina on a painting. It involves applying a layer of varnish to the painting and then heating it until the varnish cracks. This creates a network of fine cracks that makes the painting look older than it actually is.

Simulation is the technique used to create a fake signature on a painting. It involves copying the signature of a famous artist and then applying it to the painting in a way that makes it look authentic.

Pastiche is the technique used to create a fake painting in the style of an old master. It involves copying the style and techniques of an old master and then creating a new painting that looks like it could have been created by that artist.

Copy is the technique used to create a fake painting that is based on an existing painting. It involves copying the composition, colors, and brushstrokes of an existing painting and then creating a new painting that looks like the original.

Collage is the technique used to create a fake painting that is made up of parts of other paintings. It involves cutting out pieces of other paintings and then assembling them together to create a new painting.

Original is the technique used to create a fake painting that is made up of entirely new material. It involves creating a new painting that is not based on any existing painting.

Mixed media is the technique used to create a fake painting that is made up of a combination of new and old material. It involves using both new and old materials to create a new painting.

Aging is the technique used to create a fake painting that is made up of entirely new material, but is made to look like an old painting. It involves using techniques such as craquelure and patina to make the painting look older than it actually is.

Imitation is the technique used to create a fake painting that is made up of entirely new material, but is made to look like a painting by a famous artist. It involves copying the style and techniques of a famous artist and then creating a new painting that looks like it could have been created by that artist.

Pastiche is the technique used to create a fake painting that is made up of entirely new material, but is made to look like a painting from a particular period of time. It involves copying the style and techniques of a particular period of time and then creating a new painting that looks like it could have been created during that time.