Abrasive Method:
Acid-etching or sand blasting to alter the surface of a material. The material is masked and an abrasive method applied, incising a graphic into substrate.

Absorption:
The dispersal of visible light as it interacts with matter, decreasing its transmission. The end result is a modification of the material's color.

Acceleration:
The force of a knife-plotter head moving from a stopped position to its fastest linear (straight-line) speed. Measured in grams, it gives the zero-to-60 indication of plotter speed, but a better overall indication is throughput.

Access Door:
A door or panel that provides access to concealed equipment, most often electrical components, for inspection, maintenance, and repair.

Access Panel:
Removable or swinging panel, usually flush with adjoining surface, that provides access to concealed equipment or system components for inspection, maintenance, and repair.

Acetate:
A thin flexible plastic sheet usually available in roll form. Durable and stretch-resistant, this clear material is normally used as a substrate in point-of-purchase signs. Available in glossy and matt finishes.

Achromatic Colors:
Neutral colors, such as white, gray, and black, with no apparent hue properties.

Acid-Etching:
A method similar to sandblasting, used primarily for marking glass. A stencil of the artwork is either hand- or computer-cut and applied to the glass, which is then brushed with an acid mixture such as ammonium and sodium biflouride. After a specified length of time, the surface is washed and the stencil removed. Also called etching.

Acrylic:
Often used as a generic term for plastics used in sign making. Acrylic is a type of plastic (Plexiglas, Acrylite, are well known proprietary trade names) characterized by clarity, transparent and opaque color ranges, and paintablity. It also has excellent machinablity. Cast and extruded acrylics have different qualities and tolerances.

Acrylic Paint:
A type of paint or ink with an acrylic resin base, normally used in silk screening and screen-printing and when hand-painting signs.

Additive Colors:
When red, green, and blue lights (the three additive colors) come together in equal proportions, the resulting light is white. Also called "additive primaries." See also primary colors.

Adhesion:
The ability of two materials to be held together at the molecular level. Normally created by use of an adhesive such as double-sided tape or glue. Can also refer to magnetic adhesion or mechanical adhesion by suction, Velcro, etc.

Adhesive:
A material able to hold two surfaces or materials together. Often activated by heat or pressure. Examples include tape, glue, paste, synthetic resin, epoxy or silicone adhesives.

Adobe Acrobat:
Software for Portable Document Format (PDF) files that allows the reader to view and print a document as originally designed without having to install the particular program or fonts used to create the file. Software for viewing PDF files is Acrobat Reader, and software for altering published PDF files is Acrobat Distiller, both created by Adobe Systems.

Advance Notice Sign:
A sign used to provide an advance notice prior to a roadway, street, or building entrance. Similar to a directional sign, but usually announces a single destination. Also called approach sign.

Air brush:
A device used in hand-painting that utilizes compressed air to generate a fine spray of paint. As air passes through the head of the airbrush, a vacuum is created, siphoning the paint up from its container. Airbrushes come in a variety of sizes with different heads and tips depending on the detail required.

Aluminum:
A light common material used in sign panels, poles and frames.

Ambient Light:
The general level of light, or background light, in a given environment. The ambient light level is the sum of all light (direct and indirect) in a given area emitted by natural and manmade sources at a given time. It can affect the legibility of signs, and may require alterations in illumination methods.

Anchor:
Any device that secures one object to another and does not give way, as well as the process of installing those devices. In sign making, this term refers particularly to the fasteners that are used to secure awnings and fascia signs to facades. See also J-bolt.

Angle:
An extruded length of material, usually plastic, aluminum, or steel, in the shape of an L (right angle). A structural angle has rounded, or radiused, interior corners and more inherent strength than architectural angle, which has crisp, 90-degree interior corners.

Angle iron:
A length of structural iron or steel having a 90-degree (right angle) bend running parallel to the length. Used in a variety of applications including structural framework inside sign cabinets to support skin.

Animated sign:
A sign that shows motion or changes in copy or color, most often through the use of electric or electronic means.

Anodized Finish:
An electrochemical coating applied to the surface of metal, to harden, protect, and enhance the beauty and durability of metal surface. The type of finish typically applied to aluminum may include tints, colors, or clear coatings. The anodizing process builds an oxide film on the surface by making the aluminum the anode, or electrically positive element, in a suitable electrolyte.

Application:
The installation of vinyl on a surface. Two main methods are used: wet and dry. Wet application involves the use of a soapy solution or special fluid on a surface, allowing the vinyl and its transfer-tape carrier to be positioned before final placement. Dry application places the vinyl and transfer tape immediately in its final position, and usually involves hinging for setting the material.

Approach:
The area along a street or sidewalk from where a sign first becomes visible until the display is no long readable as the viewer passes by.

Approach Sign:
See advance notice sign.

Arc:
A curved line segment that is a segment of the circumference of a circle.

Architectural Signage:
A term that was coined in the 1960s to identify visual communications and way finding information in the built environment. Hence, physical enhancements to a building or space with the purpose of identifying or communicating information. See also environmental graphics, sign.

Area of Rescue Assistance:
A safe location, usually in a high-rise building, where physically challenged or incapacitated individuals are to wait for assistance in case of emergency.

Art / Artwork:
All copy, graphics, and logos used in preparing a job. See also copy, electronic art.

Ascender:
In a given typeface, the portions of the lower case b, d, f, h, k, and l that extend above the height of the lower case x. See also descender.

Aspect Ratio:
The relationship between an image's horizontal length and vertical height.

Awning:
A shelter usually constructed of non rigid materials on a supporting framework that projects from and is supported by the exterior wall of a building. An awning may or may not be illuminated and/or decorated with graphics to serve as a sign. There are also glass and metal awnings. Also called canopy.

Axis:
The geometric guidelines used to place a coordinate that determines knife and/or tool paths for plotters and routers.

Axis Swapping:
The process where sign-production software temporarily transposes a plotter's x- and y-axis. The function allows long, thin jobs along the x-axis to be cut across a vinyl sheet's width, saving material.