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For color trapping, swell any light color into a darker one
with the stroke tool. Then set to overprint in the paint palette.
It won't show up right on screen or on your digital output,
but the colors will separate properly.
Have several pictures to covert? Use Photoshop's batch convert
feature. Simply record an action by opening a photo and manipulating
all the basic steps that need to be done on all photos and
then save. Stop recording your action and then go to File
>Automate >Batch and follow the steps. What took you
an hour to open, modify and save will now be done in just
a few minutes!
To have the best quality in printing or copying, there are
certain minimum requirements that need to be met to ensure
you final vision is what you planned.
There are two types of programs used to produce artwork: vector
and bitmap. Most scanning software general sends an image
into a bitmap program as scanners see images in a pattern
of very small dots called pixels. There are programs that
can convert bitmap images into vector images (such as Adobe
Streamline). Before giving tips on scanning, here are the
differences between the two types of programs.
Vector programs use mathematical formulas to create an image.
Programs such as Illustrator, Freehand and Corel Draw are
the most common. In these you create shapes that are made
up of points and curves. When saving these files, you need
to consider several items: 1) finished size of artwork, 2)
colors used, and 3) output device. The finished size is important
because if you've created a fairly intricate piece of artwork
and your final output will be less than an inch across, then
your design will be lost. You can generally enlarge an image
as much as you want, but again, if you have small errors they
will be magnified.
Colors used is very important, especially if you have colors
that touch or overlap. While digital output devices do quite
well in this area, offset printing is not as accurate. To
combat this you have to build in trapping...that is, make
the colors overlap just a bit so that any inaccuracy in the
printing process will not be as noticeable. The final output
device is important as stated above, as well as current ink
jet printers have a tendency of causing jagged edges on otherwise
smooth designs.
Bitmap programs use square dots to build an entire image.
Programs such as Photoshop, Painter and Canvas are the most
common. In these programs you create a canvas and use "brushes"
and other tools to draw an image. When creating these images
you must consider: 1) finished size, 2) resolution, and 3)
output device.
As in Vector programs, the final output can show flaws or
lose detail. Resolution is important depending on where you
are printing your image. Copy some image off the Internet
sometime and then print it on your laser printer. Looks pretty
good, but not as good as on screen, right? That's because
the screen resolution is much lower than what is needed for
print.
The output device can help an image or hurt it. As in the
example above, too low a resolution can cause an image to
look jagged or worse.
For any printed photos (color or black and white) at 100%
of their scanned size you never need to scan higher than 300dpi
unless you plan on enlarging the image. For Newsprint: 170dpi.
For Web Pages: 72dpi.
For line-art or text you never want to scan lower than 800dpi.
1000 to 1200 is better, if you have the disk space.
It is always best to have your final image the exact size
that it will be printed. This saves disk space (which may
be crucial if you email or try to fit it on a disk) and increased
output time.
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