verdigris
(vird-uh-gree)

Verdigris is a green or bluish-green pigment. Its name comes from the Old French "vert de Grece", which literally meant "green of Greece". It was used as the primary green pigment up until around the 18th century. Think of the way copper changes color, as with an old penny, that weird looking green stuff is verdigris. (By the way, it is a poisonous chemical compound. If you come across a small child attempting to insert such a penny into a nostril, you may consider frightening him or her into sensibility with that "poisonous" part.)
Also known as: vert-de-gris, verderame, grünspan, copper acetate.
Source: arthistory.about.com

proscenium
(proh-see-nee-uh-m)

In older theaters, the proscenium is an often-ornate arch defining the front of the stage. It compromises the "fourth wall" behind which action traditionally takes place in a theatrical production. Modern theaters seldom have the proscenium.
Also known as: pros arch.
Examples: In the old Broadway theater, the gold-leaf prosceneum arch reached stage left to stage right framing an area through which the audience saw the show.
Source: theater.about.com

grisaille
(gris-eye)

Grisaille, from the French word 'gris' for gray, is a monochrome painting or drawing, usually in gray but sometimes in sepia tones. Grisaille drawing and painting from plaster casts are done as the basis of classical art training, as the technique allows the artist to concentrate on accurate rendering of form without the distraction of color.
Realist drawings in graphite and charcoal could technically be described as grisaille, but you'll find the term more frequently used to describe the monotone underpainting, also called imprimatura, which is used in traditional, layered oil painting techniques.
Also known as: grayscale, greyscale, imprimatura (when referring to paint)
Source: drawsketch.about.com

scumble
(skuhm-buh-l)

A painting technique where a thin or broken layer of color is brushed over another so that patches of the color beneath show through. It can be done with a dry brush, or by removing bits of paint with a cloth.
One of the great advantages of scumbling with pastels over other mediums is the vibrancy you can achieve with color. Possibly the best method for getting this is by scumbling after a layer of pastel has been applied, and fixed, lightly drag a soft pastel on its side across the top. This creates a broken covering of the new color over the top.
The result is visually stimulating and very textural, and careful choice of colors will produce amazing results. This method works best with the softest soft pastels.
Source: painting.about.com

ochre
(oh-ker)

Ochre or Ocher is term for both a golden-yellow or light yellow brown color and for a form of earth pigment which produces the color. The pigment can also be used to create a reddish tint known as Red ochre. The more rarely used terms Purple ochre and Brown ochre also exist for variant hues. Because of these other hues, the color Ochre is sometimes referred to as Yellow ochre.
Ochres are among the earliest pigments used by mankind, derived from naturally tinted clay containing mineral oxides. Chemically, it is hydrated iron (III) oxide. Modern artists's pigments continue to use the terms Yellow ochre and Red ochre for specific hues.
Source: en.wikipedia.org

encaustic
(en-kaw-stik)

Encaustic (which also goes by "hot wax painting") is an ancient technique. The artist heats beeswax to the liquid stage, then mixes in pigmentation. The resulting medium is applied to a surface (typically: wood). After the artist has everything "just so", heat is applied to the whole business, which results in a fusion of colored wax and wood. (Yea, verily - they become as one... an extremely durable one, at that.)
Before the wax cools, an artist can do all sorts of things to his or her encaustic piece. Metal tools or special brushes can shape and/or texture the substance (layers of which can be anywhere from thin to relief-map thick). One may even affix objects (such as coat hangers, or light bulbs) into the wax, as Jasper Johns is known for doing. Additionally, an encaustic can be polished to a final sheen, or reworked (through use of heat, again) as much as necessary until the artist is satisfied.
Source: arthistory.about.com

ferrule
(fer-uh-l)

The ferrule is the part that holds the handle and hairs together, and in shape. It's usually made from metal, but not exclusively. Mop brushes, for instance, can have a ferrule made from plastic and wire. A decent quality ferrule won't rust or come loose.
Source: painting.about.com

sienna
(see-en-uh)

Sienna is a form of limonite clay most famous in the production of oil paint pigments. Its yellow-brown colour comes from ferric oxides contained within. As a natural pigment, it (along with its chemical cousins ochre and umber) was one of the first pigments to be used by humans, and is found in many cave paintings.
Sienna, in and of itself, is sometimes referred to as "raw sienna", in order to differentiate it from "burnt sienna", which is a more common pigment than the raw form. The difference is in the process applied to burnt sienna, which is raw sienna heated to remove the water from the clay and redden its brownish colour.
Source: en.wikipedia.org

aqueous
(ey-kwee-uh-s)

A solution in which the solvent is water. It is usually shown in chemical equations by appending (aq) to the relevant formula. The word aqueous means pertaining to, related to, similar to, or dissolved in water. As water is an excellent solvent as well as naturally abundant, it is a ubiquitous solvent in chemistry.
Substances that do not dissolve well in water are called hydrophobic ('water fearing') whereas those that do are known as hydrophilic ('water-loving'). An example of a hydrophilic substance would be sodium chloride (ordinary table salt). Acids and bases are aqueous solutions, as part of their Arrhenius definitions.
Source: en.wikipedia.org

vermilion
(ver-mil-'yen)

Vermilion, sometimes spelled vermillion, when found naturally occurring, is an opaque orangish red pigment, used since antiquity, originally derived from the powdered mineral cinnabar. Chemically, the pigment is mercuric sulfide, HgS, and like all mercury compounds it is toxic. Its name is derived from the French "vermeil" which was used to mean any red dye, and which itself comes from "vermiculum", a red dye made from the insect Kermes vermilio. The word for the color red in Portuguese (vermelho) derives from this term.
Today, vermilion is most commonly artificially produced by reacting mercury with molten sulfur. Most naturally produced vermilion comes from cinnabar mined in China, giving rise to its alternative name of China red.
Source: en.wikipedia.org

serif
(ser-if)

A serif is the little extra stroke found at the end of main vertical and horizontal strokes of some letterforms. Some are subtle and others may be quite pronounced and obvious. In some cases serifs may aid in the readability o f a typeface. Serif refers, in general, to any style of type that has serifs. Fonts without serifs are called sans serif.
Source: desktoppub.about.com

chroma
(kroh-muh)

The chroma of a color is a measure of how pure or intense it is, how saturated the color is. You reduce the chroma of a paint color by adding a neutral gray with the identical value as the color you're wanting to change. Colors have three attributes -- hue, value, and chroma. In non-art speak terms, these are generally simply called color, darkness/lightness, and intensity/saturation.
Source: painting.about.com

vellum
(vel-uh-m)

Traditional vellum is a surface used for writing made from animal skin, specifically calves, lambs, or goats. The skin was processed and scraped clean, then 'polished' smooth. The side which originally had the fur on it has a slightly rougher finish to it.
In contemporary usage, the term "vellum" is used to describe paper that is relatively translucent and smooth. However, to confuse matters, the term "vellum finish" is sometimes used to describe paper with a surface texture that's got a slight tooth or roughness to it, rather than a really smooth paper. So check the actual paper, don't go by the description alone.
Source: painting.about.com

gravure
(gruh-vyoo-r)

With gravure printing an image is etched on the surface of a metal plate, the etched area is filled with ink, then the plate is rotated on a cylinder that transfers the image to the paper or other material.
Also Known As: rotogravure
In contemporary usage, the term "vellum" is used to describe paper that is relatively translucent and smooth. However, to confuse matters, the term "vellum finish" is sometimes used to describe paper with a surface texture that's got a slight tooth or roughness to it, rather than a really smooth paper. So check the actual paper, don't go by the description alone.
Source: desktoppub.about.com

intaglio
(in-tal-ee-oh)

In the various intaglio printing methods, the area of the image to be printed is recessed into the surface of the printing plate and the recessed areas are filled with ink. The incised image may be etched, engraved with chemicals or tools. The image to be printed is incised into the plates, the incisions filled with ink, and excess ink wiped from the plates. Heavy pressure is applied to transfer the ink from the plates to the paper, leaving the surface slightly raised and the back side slightly indented.
Examples: Intaglio printing is used for printing U.S. paper currency and for other fine art printmaking. Some forms of printing that use the intaglio process include engraving and gravure.
Source: desktoppub.about.com

lithography
(li-thog-ruh-fee)

With gravure printing an image is etched on the surface of a metal plate, the etched area is filled with ink, then the plate is rotated on a cylinder that transfers the image to the paper or other material.
Also Known As: lithographic printing, planographic, planography, litho
Source: desktoppub.about.com

colophon
(kol-uh-fon)

A list or description of how a book or magazine was produced is its colophon. It may contain production materials such as software, hardware, typefaces, and type of paper. Traditionally found at the back of the publication, some modern books place the colophon near the front. Some Web sites provide a colophon describing how the site was produced. The word itself is derived from the Ionian city of Colophon.
The colophon can be a simple list or may be presented in narrative, paragraph form.
Source: desktoppub.about.com

masthead
(mahst-hed)

In a magazine or a newspaper you may see the masthead on the cover or front page but in a newsletter it may be on the inside and it's not the same element.
The masthead is that section of a newsletter, typically found on the second page (but could be on any page) that lists the name of the publisher and other pertinent data. The masthead may include staff names, contributors, subscription information, addresses, logo, etc.
Source: desktoppub.about.com

pangram
(pan-gruh-m)

A sentence that uses every letter of the alphabet at least once is a pangram. It comes from the Greek “pan gramma” meaning "every letter." The goal of many pangram writers is to use all the letters, with as few repeats as possible, while still creating a sensible, clever, or meaningful sentence.
Perhaps the most familiar English language pangram is that typing tutor favorite (and font sampler text), "The quick brown fox jumps over a lazy dog."
Source: desktoppub.about.com

kerning
(kur-ning)

Kerning is the adjustment of space between pairs of letters to make them more visually appealing. It is normally applied to individual letter pairs in headlines or other large type.
Kerning is also known as letterspacing or character spacing.
Source: desktoppub.about.com

anti-alias
(an-tee-ey-lee-uh-s)

To smooth out the jagged edges of lines and shapes in digital images that have been aliased, jagged instead of straight or smoothly curving. The jagged edges of an aliased image are also called jaggies. In many graphics software applications antialiasing can be turned on or off when using "pencil", "eraser", "paint bucket", and "magic wand" tools. Not all text or artwork looks better when it is antialiased. Small text or images sometimes look too blurry when they are antialiased. Antialiasing can substantially increase the file size of images, making their printing go more slowly, and Web pages load more slowly too.
Aliasing can be annoying when the resolution of a graphics file is too low. This can occur when an image is enlarged or copied from a source for which a lower resolution was more appropriate.
Source: artlex.com

recto
(rek-toh)

The front side of any work on paper. May also be the right-hand page of a book. The opposite of verso. The front and rear sides of other two-sided objects, such as coins, medals, or panels which have a painting on each side are more often referred to as obverse and reverse.
Source: artlex.com

verso
(vur-soh)

The second or back side of any work on paper. May also be the left-hand page of a book. The opposite of recto.
Source: artlex.com

incongruity
(in-kuhn-groo-i-tee)

A state of two or more things lacking harmony, being incompatible, inconsistent, absurdly combined. Such things would be described as incongruous. This sometimes results in irony. What makes something humorous or tragic is essentially an instance of incongruity. Incongruity is an idea explored often by artists influenced by Dada and Surrealism.
Source: artlex.com

ligature
(lig-uh-choo-r)

In calligraphy and typography, two or more letters joined together to create a single character. Among the most common such combinations: æ (a+e) and Æ (A+E). Among other letters most commonly combined include oe, fi, ff, and ffl. When cast type was employed (before the digital revolution), a ligature was cast on the same body of type. Kerning, by comparison with ligature, is the technique of adjusting the spacing between two letters to bring them close enough to overlap. Some ligatures, including "æ", might be described as made by kerning. The horizontal spaces between lines of type are called leading.
Source: artlex.com

lacuna
(luh-kyoo-nuh)

An empty space or a missing part; a gap, a void. A term used most by art historians and art conservators. The plural form is lacunae or lacunas; adjectival form lacunal.
Source: artlex.com

decorum
(dih-kohr-uhm)

Conventions in matching a subject of an artwork to a style or tone appropriate to it. A kind of etiquette expected in the treatment of an artwork's content.
Source: artlex.com