DESIGN TIPS

FILE BASICS

Types of Digital Graphics

An understanding of the different types of digital graphics can improve the final look of your printed piece.

VECTOR ARTWORK

  • Involves a mathematical definition of a graphical element's position, size, shape, and color
  • Files tend to be small and efficient
  • Artwork is scalable (there is no loss of quality when enlarged)
  • Suitable for web or print
  • Used for images with line art or simple gradients

RASTER/BITMAP ARTWORK

  • Based on an array of picture elements ("pixels") tagged with color information
  • Files tend to be large
  • Not scalable - it is not recommended that you enlarge raster artwork
  • Images suitable for web are not suitable for commercial print
  • Used for images with continuous tone or texture (such as photographs)

Graphical File Formats

Different graphical file formats are suitable for different purposes. They vary in compression, and some are better for printing than others.

Compression is the encoding of information while reducing the bandwidth or bits required. Lossy compression results in the loss of some of the original data. Whereas lossless compression results in a compression ratio of about 2:1, lossy compression of image data can lead to ratios of between 10:1 and 50:1 without visibly degrading image quality.

The chart below summarizes the features of the various formats of graphical files you might place into your layout (please also see our list of preferred layout software.)

Graphical File Formats

PSD
(Photoshop)

Lossless

Yes

 

X

 

EPS
(Encapsulated PostScript)

None

Yes

Good for duotone (two-color halftone reproduction from a one-color photograph)

X

X

TIFF
(Tagged Image File Format)

Lossless

Yes

Good for photographs and other continuous-tone artwork

X

 

JPG

Lossy in variable quantities

No

Good for web usage

X

 

GIF

Not applicable (indexed colored)

No

Good for web usage; 8-bit color space

X

 

PDF
(Portable Document Format)

Several compression choices available

May have color separation problems

Avoid for photographs

X

X

More About PDFs

Portable Document Format (PDF) was developed as a means of delivering files to end users that would be the equivalent of a paper document. The user is not required to own the program that created the file (Adobe Acrobat.) It is viewable with a free program from Adobe known as Acrobat Reader.

Fonts and support graphics are simplified and embedded into the file, allowing for universal compatability. PDF supports both vector and raster art elements. Any layout developed for print is easily repurposed for web using PDF. Best of all, it can retain the integrity of the layout without compromise, while keeping the file size to a minimum.

Adobe Acrobat is not a development application used for creating layouts natively. Rather, layouts are created in another program such as Adobe InDesign or Quark, then converted to PDF format. However, Acrobat does allow for some editing of text. It also allows for simple editing tasks such as spell check, deletion, "Post-It" notes, and markup.

Acrobat Reader, on the other hand, does not allow for any editing, only review. It will also not enable you to create PDF files. In most cases, the creation of PDF files will require that you own a copy of Acrobat.

Acrobat comes with an application called Acrobat Distiller that does the following:

  • interprets PostScript code
  • resamples pixel-based images to a controllable standard
  • embeds fonts or define font substitution parameters
  • streamlines the PostScript code by eliminating any extraneous instructions not necessary for the viewing or printing of the document
  • can eliminate PostScript errors

Acrobat Distiller has the following default output settings:

  • Press (best for printing presses)
  • Print (for laser or inkjet printers)
  • Screen (for monitors/web sites)

PDF files can be used as a sort of "prepress package" containing all the data that an application-based layout and its support files contain. This has pros and cons. When time and expertise allow, control of the artwork is placed more in the hands of the designer than in those of the prepress personnel. However, when a PDF is provided to a printer, there are many limitations in controlling, realigning, and editing the artwork if needed.

More on the PDF file format from Adobe.com...

In most cases, The Forms Outlet, Inc. would prefer that you provide us your native files instead, especially if any revisions are required. Please see our list of preferred software.

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