What is Lenticular Printing?
When I was about ten I had
a Batman ring that appeared to change its image when I changed
my viewing angle. Since then I have seen printed
eyes that wink when I move them as well as any number of
other items that show dual images. What is this all about
and how does it relate to printing?
These changing images are examples
of lenticular printing. Lenticular printing is
not to be confused with holograms, a multitude of complex
processes and products created by the use of laser beams.
Lenticular printing uses lenticular files that you would
prepare in digital format (as you might create an image
file in Photoshop and at the same resolution as you normally
use for printed images; that is, 300 dpi or higher resolution).
You would provide a “before” and an “after”
image. Some lenticular printers produce “before,”
“middle,” and “after” images. One
printer even produces up to twelve separate images. Apparently,
one can more successfully achieve up/down movement with
this technology than right/left movement. However, if you
wanted the images to move from side to side, you could design
them in vertical format and than flip them sideways in the
same program.
The lenticular print provider
prepares special files and then prints them onto a plastic
material made up of very small, tightly-spaced, half-cylinder
lenses. The rear surface of this lens screen is
first coated with photosensitive emulsion, and this emulsion
is then exposed to a light source representing either different
views of the same image (creating a three-dimensional effect)
or different images altogether (creating a “flip-book,”
animation effect). The image is printed in an interlaced
manner, with segments of the various images alternating.
The lenticules (tiny lenses) cover the alternating printed
images, hiding one image while revealing another. As you
shift the printed piece in your hand, the image appears
to move because the lenticules block different portions
of the images from view as you move the printed piece in
different directions.
Lenticular printing can also
mimic depth. The lenses in this case run vertically
on the printed sheet, and the left eye sees one image while
the right eye sees a slightly different image. Together,
both eyes perceive the two images as one three-dimensional
scene.
Lenticular printing, which
used to be only a gimmick for use in toys, has become a
powerful advertising tool. A marketer can show
a before and after image or briefly show a visual display
in actual sequence of how to use the product being sold.
The lenticular printed sheet is also durable, so it can
be mailed as a postcard and can delight the recipient by
standing out from the other mail pieces.
One thing to remember with
lenticular printing is that the images must be specially
prepared with attention to fine detail. If the
angles of the lenticules are not precise or the images they
hide and reveal are inaccurate, you will not be pleased
with the effect. Closely reviewing samples provided by an
experienced lenticular printer can save you headaches. As
always, ask for proofs from your print provider as your
job progresses. When in doubt, go with traditional offset
printing. Lenticular printing is a dramatic technology but
not an easy one to master.
What is the Difference Between Brightness and Whiteness?
When referring to a paper stock, brightness
refers to the amount of light the sheet refects back to
the viewer. On a scale of 1 to 100, a sheet with a 96 brightness
would be brighter than one with a brightness of 92.
In contrast to this, whiteness refers
to the quality of light reflected back to the viewer. Is
it blue-white (a brighter-appearing white) or yellow-white?
Depending on your goals, you might choose a blue-white paper
to bring out the coolness of the imagery, for example a
snow scene. Or, if your images are of chrome and metal,
you might want a warmer, yellow-white sheet. In another
case, you might choose a yellow-white sheet for an antique
feel.
What is Synthetic Paper?
Synthetic paper is made from
a synthetic resin derived from petroleum. Although
it really is a plastic sheet, it has the appearance and
properties of paper made from wood pulp. It is white and
opaque, like wood-based paper, and it can be printed and
finished (such post-press operations as folding) just like
any sheet of paper.
Why should you care?
Synthetic paper is perfect for a menu, a reusable placemat,
or other items that will be handled repeatedly and need
to wiped down or are exposed to water. In fact, I once saw
a printed sheet of this stock under water in a fish tank.
This would be impossible with a paper-based printing stock.
Synthetic papers are also supremely tear-resistant. ID cards
or printed materials used by hikers, or indoor signs to
place in schools, gyms, and locker rooms would be ideally
suited for this printing stock.
Keep in mind that synthetic
papers must be treated differently than wood-based papers
in the printing and post-press processes, so your offset
provider needs to be familiar with the properties and requirements
of this stock. Involve your printer early in the production
process if you're considering this unconventional paper.
Also make sure your printer has experience using synthetic
papers.
[Steven Waxman is a printing consultant. He teaches corporations how to save money buying printing, brokers printing services, and teaches prepress techniques. Steven has been in the printing industry for thirty-three years working as a writer, editor, print buyer, photographer, graphic designer, art director, and production manager.]