Illustration
- Anchor Point
- 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. A common way to begin a drawing is
to create a pencil or ink drawing and scan that. This scan will 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.
- Compound Path
- A compound path is a function of PostScript that allows two
overlapping paths to act like a doughnut. (Having a "see through"
hole in the middle.) The shape representing the letter "A" is a
common example of a compound path. It the "A" is put in front of a
colored background, the color shows through the hole in the
middle. 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.
- 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.
- 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!)
- 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.
- 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.
- Masking
- An act of using a mask in an image editing program. See Mask
- 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.)
- 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.
- Path
- A term for the shape of an element in an illustration. A path,
on its own will not show on the hardcopy 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.
- 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.
- 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.
- 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.
- 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.
- Stroke
- A term in used illustration software that refers to the
printing line that is applied onto a "path."