Graphics Reference
In-Depth Information
Resolution do's and don'ts
It would be nice to be able to scan everything at 72 ppi and not have to do a thing to the
files, but you'll end up with much better results if you scan them in with more resolution
and detail than you'll end up using. The trick is to know how much more you need, and
when you're just wasting time and disk space.
If you expect to edit a photographic image, not just scale it, try scanning at 150 ppi. If you
scan at too high a resolution, then downsample—resample the image at a lower resolu-
tion. Your image may soften so much that you will find the result unacceptable.
Your best rule of thumb is to scan so your pixel dimensions are roughly double what they'll
end up on screen. If you want each image to end up about 400 pixels wide, scan at what-
ever resolution gives you approximately 800 pixels to work with. That may mean scanning
in a business card at 300 ppi but a tabloid image at only 72 ppi.
Line art can get very jagged when scanned. You'll need to scan at high resolution and then
clean up the art before you scale it down.
Scanning printed work with great type design or sharp, flat art can drive you crazy because
you're moving lovely vector art to rasters. Always scan such artwork to at least double the
resolution you'll need to show onscreen and then scale it to 50%. This will help to clean
up the edges.
After you've chosen a resolution and made your scan, don't ever scale the work up. If
you've miscalculated and scanned too small, rescan at the correct percentage.
If you have several pieces of the same type to scan, test first. Scan one, making whatever
changes you think are necessary to bring it successfully to the size at which you'll show it
in your portfolio. If you discover that you've scanned too high or too low, you have time to
adjust before scanning the rest of the batch.
in pieces and stitch together. Fortunately, there's a quick and easy fix for
that. Scan the art, and open it in Photoshop. Then use Crop and Straighten
Photos to square your art up automatically.
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Scan tiled work twice.
If you're scanning art in two pieces, you may find
that one side of the artwork is slightly brighter or darker than the other if
the artwork doesn't lie completely flat. To guard against this, scan the work
twice, the second time with the halves rotated 180 degrees. Try merging the
left side of the first pass with the right side of the second, or vice versa.
