trompe l'eoil
(trump-loy)

Literally translates from French to mean "fools the eye." Hard to paint, the trompe l'oeil piece requires meticulous attention to detail on the part of the artist. Proper sizing and every detail, nuance of light and gradation of color must be skillfully incorporated in order to make the two-dimensional work appear to be three-dimensional.
Paintings of this genre have been around since Antiquity, though they fell into disuse during the "Dark Ages" It wasn't until the Italians (re)discovered linear perspective during the Renaissance that trompe l'oeil became popular for keeps. In the 21st-century, the term "Photo-Realism" would be equally applicable to this type of painting.
Source: arthistory.about.com

frottage
(fraw-tahzh)

The technique of rubbing with crayon or graphite on a piece of paper which has been placed over an object, or an image achieved in this way. Also simply referred to as rubbing. Such impressions are usually made from such highly textured subjects as leaves, wood, wire screen, gravestones, and manhole covers.
It was a technique especially employed by surrealists, one of whom, Max Ernst (German, 1891-1976), first introduced frottage in his works in 1925, often employing such rubbings as part of a collage, or combining frottage with painting techniques.
Source: artlex.com

faux
(foh)

From the French, faux literally means "false" or "artificial". In other words, you're not looking the genuine article. To be blunt, faux(-anything) in art is fake(-anything).
One can use the adjective "faux" in front of just about any man-made material created to simulate something organic. Lots of decorative objects utilize faux materials. Faux bois looks like wood, faux porphyry looks like stone, faux pearls look like real pearls, faux leather doesn't look a thing like leather and faux fur looks frightful, but was a lot of fun in the 60s. Eye of the beholder, and all that.
Source: arthistory.about.com

craquelure
(krak-loo-r)

Craquelure is a term used for the network of fine cracks that can appear on a painting, either over the whole painting or just in parts. (Take a look at an example of craquelure from the Fine Arts Conservancy.)
Craquelure differs depending on whether the painting was done on canvas or a wooden panel, as well as by what was used for the ground and the type of paint used. It's said an experienced art expert can distinguish between different types of wood used as a support according to the craquelure that's developed, which follows the grain of the wood.
Source: painting.about.com

fresco
(fres-koh)

A fresco is both a painting done on a wall and the technique used to create such a painting. A fresco is made using pigments mixed with water painted onto a wall when the plaster is still wet. A fresco painted on dry plaster, called fresco secco, is less durable than a true fresco, or buon fresco. Arguably the most famous fresco is on the ceiling of the Sistine Chapel, painted by Michelangelo.
Source: painting.about.com

impasto
(im-pahs-toe)

A painting technique, impasto is a thick application of paint (usually oil) that makes no attempt to look smooth. Instead, impasto is unabashedly proud to be textured, and exists to show off brush and palette knife marks. Just think of nearly any van Gogh painting to get a good visual.
Source: arthistory.about.com

quadratura
(kwa-druh-chur-a)

Quadratura is a term that emerged during the Baroque period to describe a type of ceiling painting (which had been going on for centuries). An artist would paint, from scaffolding, all sorts of fictitious architecture on to what was, essentially, a flat surface. The end results looked three-dimensional, and might have featured little statues in niches, ceiling ribs meeting curved walls and "openings" that allowed viewers to gaze upon the "sky". All of these illusions were rendered in perfect perspective to completely fool the eye.
Source: arthistory.about.com

caliper
(kal-uh-per)

An instrument used to measure the thickness or diameter of an object. It consists of a pair of movable metal or wooden arms with curved, pointed ends, hinged together; or, having a fixed and a movable arm on a graduated stock. A sculptor can take an exact measurements from a model with a caliper. Inverted measurements, as well as scaled enlargements and reductions can be obtained with calipers.
Source: www.artlex.com