VBU VECTOR GLOSSARY
phrased by =Cloxboy

Arrow
A tool that selects, configures, moves, and reshapes objects/lines/paths/anchors that you have created.

Anchor Point (see Nodes)
An anchor point is the part of a path that "ties the path down to the page." A line will have at least two anchor points on either end. It will have additional anchor points at every kink and corner. A curve will have an anchor point on either side of it and may optionally have additional anchor points somewhere on the curve itself. Anchor points do not print out but they shape the paths that appear on the hardcopy.

Auto Trace
A function in illustration software that creates paths along the edges of a scanned sketch/image. A common way to begin a drawing is to create a pencil or ink drawing and scan them. The scan will then be used as a template over which the auto tracing occurs. The next step is typically to clean up the paths the auto trace function created and then discard the template scan file. There is significant concern when using auto trace functions that the shapes will be overly complex (too many anchor points) and will not output. This is a leading cause of output failure.

Bezier
The term used to describe the way in which illustration software uses anchor points and control handles to create shapes. Bezier illustration and Bezier curves are at the foundation of the PostScript language and are even found within PostScript type 1 outline fonts.

Blend
A function in illustration software that allows the creation of intermediate shapes from two masters. These beginning and ending shapes can vary in both shape and color. The user inputs the desired number of steps and the software creates the new, intermediate shapes. This function is used primarily to create realistic highlights in artwork. There is a concern over the poor results that occur if there are too many or too few steps requested by the user.

Bounding Box
A function in the PostScript language that describes a rectangular shape just large enough to contain all elements of a design or illustration. A bounding box does not print but is always present to communicate information about the shape and size of the design or illustration.

Clipping Path
A function of the PostScript language that allows one shape to mask another. A clipping path shape acts much like a cookie cutter. The term clipping path does not appear on the menus of illustration software but instead commands like "Mask" (Adobe Illustrator) or "Paste Inside" (Aldus FreeHand) use this facet of PostScript. Excessive use of clipping paths can lead to files that will not output.

Closed path
A path that is continuous and has no beginning or end; a circle is an example of a closed path.

Compound Path
Compound paths consists of two or more paths that interact with each other. Compound paths are used when you need to show a part of underlying object through a hole in another object. The shape representing the letter "A" is a common example of a compound path. Illustration software allows the user to create their own compound paths from two or more paths.

Control Handle
A handle that extends from an anchor point that is used to create a curved shape in a path. Both the length and angle affect the shape achieved. The length will affect the depth of the curve and the angle will affect the angle at which the path exits from the anchor point.

Dots per inch (DPI)
A measure of printing resolution, in particular the number of individual dots of ink a printer or toner can produce within a linear one-inch (2.54 cm) space.

Element
An element is one object that makes up part of an illustration. On a drawing of a cat, one whisker would like be an individual element. (Drawings are created element by element.)

EPS
Encapsulated PostScript. A file format commonly used for photographic and drawn graphics. An EPS file is created and later placed onto a page layout in a page assembly program.

Export
A term used in some illustration programs that allows the drawing to be saved to the hard disk in a commonly readable format (usually EPS.) This allows the drawings to be placed into a page layout.

Eyedropper Tool
The Eyedropper Tool defines the foreground and background color. The Eyedropper Tool is used to pick up and copy a color from one area or image object to another.

Fill
A menu command that allows a path to be filled with a color or tint.

Filter
A function for special effects. It is possible to apply a filter to artwork to achieve many different looks that would be difficult with manual drawing techniques. There is a concern over excessive use of filters creating artwork that is too complex to output.

Flatness
A setting in PostScript illustration software. Flatness controls the allowable laser beam error artwork is printed. (A six sided STOP sign would be a good example of a circle with very high flatness.) To decrease output times increase the flatness setting. A flatness setting of 3 will not be visible in the output but will shorten output time. (Significantly!)

Gradient Tool/Graduated Fill
A command within illustration software that allows elements within the illustration to be filled with a smooth transition between two colors.

Layers
A function within illustration software that allows the user to organize their drawing. As an example it would be likely to see a drawing with layer names such as: Background, tablecloth, plate, pasta, sauce, type. Layers do not affect any color separation capabilities; they are simply an organizational aid. It is recommended to always use layers.

Line Weight
A term referring to the thickness of a printing line. Expressed in points line weight is adjustable over a wide range and a line can be colored at will. It is not uncommon to draw shapes with a line weight of zero and use only the fill color to define the shape.

Live Transparency
Refers to any transparent attributes that are specified but not yet executed (flattened). Keeping transparent attributes live lets their properties be changed at any time before output, or in the case of Illustrator, explicit flattening.

Magic Wand Tool
A tool in Photoshop used to quickly select a part of a picture. If clicked on a the fender of a red car, the magic wand will select the entire fender and maybe the hood and door. A setting called "tolerance" allows the user to define the relative selectivity of the magic wand. A tight tolerance and the magic wand will only select the highlights of the car fender. A loose tolerance and the magic wand will select the green trees behind the car. The selections made by this tool always select areas that are connected and not divided.

Mask
A function within image editing software that allows the user to restrict their image edits to only a part of the image. A mask can have a hard or soft edge allowing the user to achieve a variety of obvious or subtle effects.

Mesh Tool
Tonal gradations can also be created via Illustrator's Gradient Mesh tool. This tool is used to render complex gradations and shapes.

Nodes (see Anchor Point)
Nodes or anchor points are the fundamental in path editing. Get to know the various types of nodes including symmetrical, smooth, cusp and tangent nodes.

Object
An object is one piece that makes up of an illustration. On a drawing of a cat, one whisker would like be an individual object. (Drawings are created object by object.)

Opacity
A characteristic of painting and other tools within image editing software. By adjusting opacity to a percentage of less than 100%, the user can paint a color onto an image and allow some of the image beneath to show through. (Paint with transparent paint versus opaque paint.) This same characteristic is available while performing image assembly steps and allows one image to be transparently floated in front of or behind another.

Open Path
A path has a beginning and an end. For example, a horizontal rule is an open path.

Overprint
A term used to describe the characteristic of an overlapping foreground element allowing a background element to print in the same area. Overprint is the opposite of knockout. The overprint function is activated on an element by element basis in illustration software and can be selectively applied to the line and/or the fill of the object.

Paintbrush Tool
The paintbrush tool lets you paint colored strokes using a variety of artistic brush styles. Paintbrush strokes can be edited in the same manner as paths, and existing paths can be decorated with a desired brush style.

Path
A path is made up of one or more straight or curved segments. The beginning and end of each segment is marked by anchor points, which work like pins holding wire in place. A path on its own will not show on a hard copy until it has a line weight and color attribute (or fill) assigned to it.

Path Splitting
When a path becomes too complex (more than about 450 anchor points on one path) one risks having the illustration fail to output. To avoid this, the long path can be split into two or more segments. This path splitting function can be manually executed or the software can be set-p in such a way so that in will monitor path complexity and automatically split when needed. Automatic path splitting is not always reliable.

Patterned Fill
A user defined fill that allows for a complex, repeating pattern to be defined and used to fill elements within the illustration. The use of patterned fills is one of the leading causes of output failures. It should be used sparingly.

Pen Tool
The primary drawing tool in PostScript illustration software. The pen tool allows the user to position anchor points and control the shape of the line by controlling the control handles that extend from the anchor points.

Pencil Tool/Freehand Drawing Tool
A tool found within illustration software that allows the user to create freeform shapes as if with a pencil. Natural sketching and scribbling are possible with this tool.

PICT File
A graphic file format for line-art and photo graphic use. Not a preferred file format due to inconsistent color results on hard copy.

Pixel
The smallest building block within a scanned line-art or photographic image. A pixel is the small square picture element that is filled with a color, or black or white. Pixels come in various sizes and their size is expressed in terms of resolution. Resolution is measured in pixels per inch (PPI.)

PostScript Illustration Program
A general term used to describe powerful drawing software that relys on drawing commands and features found within the PostScript page description language. The two most common examples of PostScript illustration programs are Aldus FreeHand and Adobe Illustrator.

Rotate
A function found within image editing software that allows all or part of a pixel image to be rotated by any number of degrees. Rotation in 90° increments is fast and carries no quality penalty but this is not the case for other angles. This is why it is important to carefully orient artwork on a scanner so that rotation will not be necessary.

Shape Tools
You can create many objects in Illustrator by starting with basic shapes. The shape tools let you easily create rectangles, ellipses, polygons, spirals, and stars. To draw a shape, select the appropriate shape tool from the toolbar, and click and drag in the artwork window.

Stacking Order
A term in used in illustration software to describe the element by element drawing order that occurs. It is common to draw background elements first and then draw foreground elements "stacking" them in front of the background elements. It is also possible to later alter the stacking order and move particular elements in front of, or behind other elements. While "overprinting" is possible, typically foreground elements "knockout" background elements. Even a foreground element with a 5% tint of a color will completely knockout a darker solid that may be behind.

Stroke
A term in used illustration software that refers to the printing line that is applied onto a "path."

Stoke Weight
A term that refers to the line thickness that is applied to a "path" in illustration software. When applied, half of the thickness extends to either side of the path.

Direct Selection Tool/Subselect
This tool selects and moves individual paths, anchors, shapes and segments.

Text Box
A text box is an element on a page containing headline or body copy. A text box can be moved independently of any other text box on the page and can be adjusted in width and depth to change the copy flow. Text can be caused to flow from one text box to another allowing a multi-column layout or allowing an article to begin in the front, and continue in the back of a publication.

Text Wrap
A term used in page layout software that refers to the way lines of text can be shaped to follow the edge of a graphic.

Type Tool
The Type tool lets you add text to your image. You can format the text in many ways, including font, size, style, color, alignment, horizontal or vertical orientation, kerning, leading, tracking, indenting and line spacing.

Vector Graphics
Is the use of geometrical primitives such as points, lines, curves, and polygons, which are all based upon mathematical equations to represent images in computer graphics.

Virtual Memory
A computer term for a performance enhancing feature of some software. Virtual memory is a process where hard disk storage space is borrowed and caused to act as if it were additional RAM. The system will then be able to perform more complex functions just as if it had the additional RAM memory actually installed. See also RAM.

References
- Binary Graphics, Inc., On-line Glossary
[link]
- Brown University Wiki, CIS Documentation, Illustrator Tutorial
[link]
- Wikipeida, the free encyclopedia, Vector Graphics
[link]
- Bloomsburg University Virtual Training Help Center, Tutorials
[link]
- Kevin Hulsey Illustration, Inc, Illustration Tutorials
[link]
- Adobe Illustrator User Guide
- Adobe Illustrator Adobe.com