138 Graphic Communications
points. The other points that defi ne the shape of the
curve are called handles, tangent points, or nodes.
Attached to each handle are two control points. The
shape of the curve can be modifi ed by moving the
handles or the control points.
There are several advantages to using vector images:
• Shapes can be resized without degradation
because objects are defi ned geometrically.
• The images print the same, even when scaled
to different sizes, and can be represented at any
resolution, which makes them more fl exible than
bitmapped images.
• A computer can store vector images very
effi ciently, making them ideal for high-resolution
output.
Digital Page
Composition
The assembly of text and graphic images
into the fi nal page is accomplished using a page
composer. The most widely used page composition
software packages today are Adobe® InDesign® and
QuarkXPress®. Although the specifi c operations are
somewhat different, an experienced operator can
use either program to combine text and graphics and
create a fi le in PostScript®. A PostScript® fi le can be
output to a laser printer, platesetter, or even directly
to a digital press.
Composition Software
Features
The features offered by different page composition
programs vary in details, but have many features in
common. See Figure 7-21. A menu bar occupies the
top of the screen, while scroll bars are on the bottom
and one side. The scroll bars are used to shift the
screen view up and down or left and right.
Pasteboard
A major portion of the screen display includes the
page or pages being laid out and a work area, usually
called the pasteboard. This area of the screen is used
for temporary storage of layout elements (such as a
piece of art or a section of typeset material) before
moving them onto the layout page. The pasteboard
can also be used to try out ideas for design elements,
type treatments, and other composition changes.
Page Grid
The page grid, sometimes called a frame or
baseline grid, is a nonprinted set of guidelines on
each layout page. Guidelines for margins, columns,
gutters, and other basic page elements are included
in the grid. One important function of the grid is to
align type horizontally when the page is arranged in
two or more columns. The operator may choose to
display or hide the grid lines.
Selected line
Figure 7-19. When a line is selected on a vector image,
the nodes will be visible. The object can be modifi ed
by grabbing and dragging the line.
Handle
Anchor point
Figure 7-20. By moving the handles, or the control
points, you can modify the shape of a Bezier curve.