Page 15 - Adobe Photoshop CC 2020

STAGE 1 / Compositing Images and Artwork

Technically speaking, compositing is the process of combining any two or more objects (images,
text, illustrations, etc.) into an overall design. The ad you’re building in this project requires
compositing three digital photographs, as well as title treatment and logo files that were created in
Adobe Illustrator by other designers. The various elements that make up the finished artwork are
fairly representative of the type of work you can (and probably will) create in Photoshop.

Types of Images
There are two primary types of digital artwork: vector graphics and raster images.
Vector graphics are composed of mathematical descriptions of a series of lines and shapes.
Vector graphics are resolution independent; they can be freely enlarged or reduced, and they are
automatically output at the resolution of the output device. The shapes that you create in Adobe
InDesign, or in drawing applications, such as Adobe Illustrator, are vector graphics.
Raster images, such as photographs, are made up of a grid of independent pixels (rasters or bits)
in rows and columns (called a bitmap). Raster files are resolution dependent; their resolution is
fixed, and is determined when you scan, photograph, or otherwise create the file. You can typically
reduce raster images, but you cannot significantly enlarge them without losing image quality.
Line art (also called a bitmap image) is actually a type of raster image, made up entirely of
100% solid areas. The pixels in a line-art image have only two options: they can be all black or all
white. Examples of line art are UPC bar codes or pen-and-ink drawings.

Screen Ruling
The file that you will be building in this project is intended to be printed, so you have Note:
to build the new file with the appropriate settings for commercial printing. When
reproducing a photograph on a printing press, the image must be converted into a Despite their origins in
set of printable dots that fool the eye into believing it sees continuous tones. Prior pre-digital print work-
to image-editing software, pictures that were being prepared for printing on a press flows, these terms persist
were photographed through a screen to create a grid of halftone dots that simulate in the digital environ-
continuous tone, resulting is a halftone image. Light tones in a photograph are ment.
represented as small halftone dots; dark tones become large halftone dots.
The screens used to create the halftone images had a finite number of available dots in a
horizontal or vertical inch. That number was the screen ruling, or lines per inch (lpi) of the
halftone. A screen ruling of 133 lpi means that in a square inch; there are 133 × 133 (17,689)
possible locations for a halftone dot. If the screen ruling is decreased, there are fewer total halftone
dots, producing a grainier image. If the screen ruling is increased, there are more halftone dots,
producing a clearer image.
Line screen is a finite number based on a combination of the intended output device and
paper. You can’t randomly select a line screen. Ask your printer what line screen will be used before
you begin creating your images. If you can’t find out ahead of time or if you’re unsure, follow these
general guidelines:
• Newspaper or newsprint: 85–100 lpi
• Magazine or general commercial printing: 133–150 lpi

• Premium-quality-paper jobs (such as art books or annual reports): 150–175 lpi;
some specialty jobs might use 200 lpi or more

Project 1: Music CD Artwork 27