lenticular printmaking
Artists throughout the ages have worked on the problem of representing three-dimensional
space on a two dimensional plane. Several of the most effective attempts
to capture realistic space rely on human stereoscopic vision; each eye
sees a slightly different view. This approach applied to photography made
stereograph viewers a common site in parlors in the US 100 years ago. In
the 50's small novelty items in which photographic images flipped from
one to another appeared in cereal boxes and on political pins. After lying
dormant for half a century, advances in digital imaging allow us to create
spectacular three-dimensional images using lenticular technology.
A
lenticular image allows the viewer to see a series of "frames" (usually
2 to 24) sequentially. By carefully crafting these frames, the
artist can create animation, depth and/or morphing of images.
To
create lenticular images, the source images are developed in
image creation software like Adobe Photoshop. A series of variations
on the image are saved as separate files. Each of these variations
becomes a "frame" in the finished lenticular print.
In
order to create depth in a lenticular image, the artist uses
Photoshop to develop a set of "frames" which use horizontal
offset of elements in the image to place these elements on different
virtual planes. Elements which are designed to recede into the
background are offset to the left; elements designed to project
forward of the picture plane are offset to the right. Elements
can also be turned on and off in sequence to give the impression
of blinking. To create movement, elements are altered in form
and/or position evenly across all frames.
The
resultant frame set is then interlaced together in linear strips
that match the lenticular lens. This lens is a piece of plastic,
with a series of parallel lens or lenticules embossed into one
surface. After the interlaced image is printed, it is aligned
with the lens, so that the viewer sees only one frame at a time.
As the viewer moves by the image, all of the frames are seen
in sequence, creating the illusion of movement, depth, animation,
morphing or 3-dimensional space that the artist set up in the
original frames.
A
specialized lenticular software like Flip!, can interlace 18
or more images and create test patterns which are used to determine
the proper pitch or increment (to the 1000 of an inch) to interlace
for a perfect match with the lens. Each lens, combined with different
printers, inks and paper may require a different pitch.
The
images created can become quite large as the pitch of the lens
is multiplied by the number of layers and determines the dpi
of the final image. For example an image with 10 frames interlaced
for a 40-line lens creates an image with 400ppi. To have enough
computing power for the 22 x 28 inch images for this portfolio,
the Digital Atelier artists used Intergraph's TDZ ViZual Workstation
with dual Intel processors.
A
variety of lenses are created for different purposes with lenticules
per inch (lpi) ranging from 10 to 300. Some have great depth
for three-dimensional representation while others are designed
for flip and animation. Lenses manufactured from different materials
are available, including ultra thin (4mil) lenticular sheets,
lenticular lens patterns for the billboard market and flexible
lens for the apparel market. Companies like Microlens Technology
sell a wide variety of lens.
As little as a year ago the only way to make a lenticular image
would be to spend $5,000-10,000 to have it produced with offset
lithography. Today the
use of high-resolution inkjet printers like the Mutoh Falcon and the Epson
9500 make it possible for an individual to create lenticular images up to 48" x
96", the current maximum lens size. The higher the number of lenticules
per inch (lpi) the higher the printer resolution must be. A 10-15 lpi lens
can be used with lower resolution printers.
Only
pigmented inks or dye-based inks with archival properties (e.g.
Lysonic inks) are used for fine art inkjet prints. While paper
may be adequate for small lenticular images, film is necessary
for large ones since shrinking, expansion or stretching of the
substrate can cause misalignment.
Because
of the illusion of movement and depth in the image, there is
a level of ambiguity that engages and involves the viewer. This
is art that cannot be understood in a glance. However the current
convergence of software, lens and high-resolution ink jet printers
make this emerging technology a new challenge and opportunity
for artists who are interested in pushing boundaries.
Digital
Atelier
Dorothy Simpson Krause, Bonny Lhotka,
February 2002