Datasheet

What Image Resolution to Use
Some people generalize and suggest using 300 ppi as a standard resolution for images
going to print. For the Web, it is usually accepted that images should be 72 ppi. While
these are pretty good as general-purpose guidelines, they don’t tell the entire story of what
resolution to use. For example, 300 ppi may be more than is necessary for all home print-
ers, but it may actually be too little for demanding output (such as film recorder output).
Because monitor resolutions can vary, your 72 ppi image on a 96 dpi screen would actu-
ally be about 75 percent of the intended size. Neither choice is likely to totally ruin your
output, in most cases, but it can compromise what you expect.
Because output differs in how it applies image information, there is no one universal
magic formula to figure out what resolution to use. Each output type has a target range
(minimum and maximum), based on its capability to process and use image information.
Once you know the range you need, you simply use that range as a target when working on
an image. Know what your printing service or printer manufacturer recommends for out-
put on the devices you use. This may require reading the manuals or calling the printing
service to find out. The optimal range is the range where the image will perform the best
when applied; it is possible to get acceptable results by going outside the range depending
on how you implement the image and the results that you expect.
Table 1.1 shows the approximate resolutions to use for your images, depending on
how you want to use them. An image sent to a device that uses a specified output resolu-
tion should have a specific target ppi. The table shows some real-world examples of out-
put resolution and workable ppi ranges. Formulas used for the calculations are shown in
the Calculation Used column; square brackets in the calculations indicate the range of
values used to determine the lowest and highest resolution acceptable in that medium.
Note that these resolutions are suggested and not absolute. Images will still print
and display at other resolutions, but the results may not be predictable or efficient.
MEDIUM OUTPUT APPROXIMATE IMAGE CALCULATION
RESOLUTION FILE RESOLUTION USED
Web 72–96 dpi (monitor) 72–96 ppi ppi = dpi
Inkjet (stochastic) 720 dpi 180–234 ppi [1 to 1.3] × (dpi / 4)
Inkjet 6 color (stochastic) 1440 dpi 240-312 ppi [1 to 1.3] × (dpi / 6)
Halftone, low resolution 75–100 lpi 116–200 ppi [1.55 to 2] × lpi
Halftone, normal resolution 133–150 lpi 233–350 ppi [1.55 to 2] × lpi
Halftone, high resolution 175–200 lpi 271–400 ppi [1.55 to 2] × lpi
Line art 600–3000 dpi 600–1342 ppi (dpi/600)
1
⁄
2
× 600
Film recorder 4K (35mm) 2731 × 4096 pixels Total pixels
Film recorder 8K (6 × 9cm) 5461 × 8192 pixels Total pixels
Table 1.1
Approximate
Resolution for
Various Media
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