3D is currently a media darling. It’s in the cinemas with blockbusters like the photorealistic Avatar, Beowulf and Alice in Wonderland, or animations like Up!, A Christmas Carol and Coraline.

Pixar’s Toy Story 1 & 2 were re-rendered and re-released in 3D last year, while this year’s Toy Story 3 will be 3D from the start. 3D television and computer monitors are being launched this year for the high end of the consumer market and Sky Sports is already testing out 3D large screen TV football coverage in a few UK pubs. Last autumn Channel 4 ran a themed 3D week, showing a series of old movies and documentaries that could be viewed on conventional TV sets using free eyeframe filters distributed through Sainsburys stores.

So, can printing take advantage of the 3D trend, even if it’s a flash in the pan? Yes indeed, and here’s how.

The movie technology

Pedants will point out that ‘3D’ movies and TV are actually stereoscopy, ie visual depth simulation. Basically two images are shot side by side on either two cameras bolted together, or through beam-splitters on lenses. Each sees a slightly different angle of view, corresponding to the viewpoint seen by each eye.

The technique used for movies and some printing is called anaglyph, where the two images are superimposed in projection. The audience wears eyeframe filters so each eye only sees one image. The brain does the rest, interpreting the different views as depth.

3D stereoscopic movies have been around since the 1950s, and originally were in black and white but required the audience to wear cardboard anaglyph eyeframes with red and cyan or green lenses. This is a different kettle of fish to 3D ‘CGI’ computer graphic imaging for 2D projection, which hit the cinemas in 1982 with the release of the movies Tron and Star Trek II, though what really caught the public eye were the photorealistic renderings of Jurassic Park and Terminator 2 in the early 1990s.

Avatar, released last December, is director James Cameron’s first 3D stereoscopic movie. Before that he used ground-breaking 3D CGI for 2D viewing in The Abyss (1989), Terminator 2 (1991) and Titanic (1997). Avatar merges live action with extensive GGIand motion capture for its blue aliens and flying dragons, but what really stands out is the quality of its 3D stereoscopy, which gives realistic continuous depth rather than the layered effect of some early efforts. Like most of the current wave of 3D movies, Avatar works in full colour. There are at least three different full-colour 3D cinema projection systems around at present: RealD, Disney-3D and Sony 3D. Avatar tends to use RealD, a very effective method of a single standard projector fitted with a synchronized rapidly rotating filter that alters the polarization of the light for the left and right eye views. The audience wears cheap eyeframes with opposite-polarity filters for each eye.

Another method, used for computer monitors and some of the forthcoming 3D TVs, alternately shows full colour left and right views, switching rapidly. The viewer wears ‘active’ eyeframes with LCD lenses that alternately black out the left and right sides in sync with the monitor. Some manufacturers are working on 3D TV that won’t need eyeframes, but there’s no common standard yet.

So how do you print 3D?

It’s easy to re-render 3D graphics for two stereoscopic views, although there doesn’t seem to be any way of reproducing the Avatar-style fullcolour polarising effect in print. But there are other ways to print a real depth simulation. Printing can be done with anaglyph effects for viewing through red and cyan eyeframes.

Setting up the images is easy with low cost software and any printing process can be used. However the colour filter viewers are a distracting nuisance and the images are downright ugly when viewed without the eyeframes.

Fortunately there’s a better way. Lenticular imaging using special grooved plastic lens materials gives the best all-round printed 3D and animation effects. It can be viewed anywhere, with no need for special eyeframes or anything else. The effect can be very attractive.

Preparation and printing is very fiddly, but this is the best 3D print method we’re likely to get, so we’ll concentrate on that. Lenticular is more popular in mainland Europe than the UK, and according to DP Lenticular, a supplier of the lens material, lenticular products that appear in the UK are often printed abroad. However, powerful computers and image processing software can now take a lot of the pain out of the complex pre-press stages. New printing technologies (some digital, some not) can print directly onto the back of the lens material instead of having to laminate printed paper sheets in close register.

Lenticular images can appear to be three dimensional, or they can suddenly ‘flip’ between different images, or gradually ‘morph’ or ‘zoom’ between them, or they can appear to move with multi-frame animations that can be looped for continuous motion. Several effects can be combined at once.

Catching the eye

Any of these effects is literally eye-catching, which is why lenticular is so often used for advertising or promotional work. Examples range from ‘novelty’ postage stamps, greetings cards, playing cards, mouse mats, magazine and book covers, DVD/CD covers, labels and packaging, plus point of sale displays such as shelf edges, wobblers, counter displays, illuminated pump displays in bars, or vending machine covers, all the way up to large format backlit signage for shopping malls, stations and airports. A lenticular print may also be tipped into other printed products, such as direct mail, packaging or magazine inserts.

Lenticular works by splitting multiple images into hundreds of narrow stripes, then alternating them side by side in regular order, called interlacing. These are then displayed behind special optically clear plastic with a series of parallel grooves forming lenses, with one lens per set of stripes. At the optimum viewing distance the lenses are barely apparent. The distance between your eyes means that each looks through the lenses from a slightly different angle, with lens refraction ensuring that each eye then sees a different set of image stripes. This gives the depth effect. The other effects – morph, flip, animation and so on, don’t use stereoscopy but rely on the viewpoint moving, as someone walks past a display or turns a lenticular image in their hands. It’s possible to use true stereoscopic images captured with special cameras, including the £450 consumer level Fujifilm Real 3D W1, introduced last year.

To support this Fujifilm offers a lenticular print service to its customers, currently by transmitting the digital files to Japan for printing, and transporting those back for fulfilment. The company has just announced a semiportable dye sublimation lenticular printer aimed at ‘event’ photographers, who might sell 3D novelty prints at a wedding or sports day. Actually most commercial lenticular designers opt to start with conventional 2D images and split them into layers of different apparent depth (see p25). It’s not true 3D but it makes the main subject, or lettering, appear to stand in front of its background.

HumanEyes ups the ante

There’s a surprisingly wide choice of software available, at prices ranging from £20 to several thousand pounds. This is generally divided into creative utilities for setting up effects such as 3D, flip and animation; and production utilities that calculate and generate the interlaced output files for a given lens material and pitch.

Lenticular software was a fairly low key speciality until HumanEyes, an Israeli developer with a talent for marketing, appeared on the scene in 2004. It gained an instant high publicity profile in the print market thanks to Benny Landa, the charismatic founder and former CEO of digital press maker Indigo, who invested in HumanEyes and is chairman of its board.This is a twin-level software system, that is split into a £199 preparation program (currently called Creative3D) aimed at designers, and an output program (currently called Producer3D), with a sliding scale of prices depending on the target print process and format.

However Producer3D is expensive (starting around £5000 but rising to £16,000 for large offset presses), which limited its take-up. Last year HumanEyes introduced a ‘rental scheme’ over the first three or 12 months, which eases the entry cost until the jobs start to pay for it. Nevertheless it only has a handful of UK users, mainly with either UV litho presses for smallish formats, or large format UV flatbed inkjets for vending and gaming machine panels.

Until recently HumanEyes was distributed in the UK by Positive Focus, but that company went into liquidation in January. Until a replacement is appointed the software can be supplied and supported directly from Israel.

Lens materials

DPLenticular in Dublin is the main supplier of lenticular lens materials in Europe, exclusively distributing the Lenstar material from Pacur in the USA.
Pacur supplies a range of pre-cut sizes suited to formats from the main offset press manufacturers, from small sizes up to the ‘VLF’ formats for large packaging machines. Thicknesses vary from 262 to 838 microns: generally the finer the pitch, the thinner and more flexible the plastic, so it is better for smaller formats such as greetings cards. However, thicker lenses with coarser pitches allow more interlaces and thus a better visual effect, but they need to be viewed from a greater distance.

DP Lenticular’s founder and managing director Daniel Pierret sees market education as an important part of his activities. Although he doesn’t sell software, he offers information and practical advice to designers and printers who wish to get into this market. ‘We sell the plastic and make money from this’ he says. ‘To help customers we organize on-site training and we have the best support on the market. We continue to assist customers after sales and give them tips. This is very important to us: other companies cannot offer this level of assistance. ‘We also organise meetings with salespeople working at printers to help them understand lenticular better, so they can sell it to their own customers,’ he adds. ‘We will also forward commercial enquiries about lenticular to our printer customers.’ The company’s website is a good source of information too, including hints and tips on production and a gallery of real lenticular jobs that show its possibilities, plus links to Pacur, which also has extensive information online.

Digital printing

Some digital printers can print directly onto the back of the plastic lenses. These include HP Indigo presses, UV flatbed inkjets and DI litho presses with UV inks. Here the main technical issue is resolution, which determines the number of interlaced stripes that can be printed: low resolution means you can’t get smooth transitions on thin fine-pitched lenses. I f you pre-print onto paper and laminate, then the choice of printers opens up, but this takes more care because the printed stripes must be aligned precisely to the lens during lamination. Digital toner printers notoriously heat and dehumidify the paper so it changes size.

You’d need careful calibration and a controlled atmosphere to compensate for this. Mr Pierret is sceptical about printing lenticular digitally for small formats. He reckons that the high price of preparation means that you need long runs to pay for it, so you may as well use offset presses with UV inks. Kodak has also demonstrated remarkably good UV flexo printing onto thin lenses using its high resolution Flexcel NX plate system.

But this may be overly pessimistic: lenticular would work well with personalisation or localised messages, where the same basic image preparation can be combined with variable messages. In that case, digital printing could be economically viable.

As proof of this, HumanEyes has set up Snapily, an online personalised consumer print ordering website (www.snapily.com) linked to a digital print site in the USA. This uses a digital printing system that marketing manager Shahar Bin-Nun declines to identify: ‘it’s as much about the workflow we have developed as the printer,’ he said. One of the older HP Indigo 2000 models is a likely candidate. Mr Bin-Nun mentioned separately that these printed very well on lenticular plastic. Current 3000/3050/7000 models can’t do it, he says, though it’s unclear whether this is due to the ink or the imaging process.

A Snapily production site may be set up in Europe in future, Mr Bin-Nun says. The company is also planning to launch a professional printing operation for advertisers and photographers, which will offer trade services to other printers.

Digitally imaged (DI) litho presses seems to be a good compromise, as they have the high resolutions needed for small thin lenticular sheets, but are economical for shortish runs. The first HumanEyes user in the UK, Terry Smith, printed lenticular sheets with a KBA Karat 74 DI press and IR drying. More recently Presstek has introduced a UV curing option for its DImodels and cites lenticular as a potential application.

For large format lenticular on thick lenses, UV flatbed inkjets work well at a technical level, producing very effective displays that look great when backlit. You’ll often see these big machines printing onto lenticular materials as demos at trade shows.

However, there doesn’t seem to be much demand for such large format lenticular displays in the real world. If you walk around a city, the moving displays in streets and stations all tend to be roller blind, slatted or increasingly all-digital plasma or LED screens, Mr Bin-Nun points out. Instead the inkjet applications tend to be mid-sized illuminated displays for light boxes or drinks pumps in pubs, clubs and restaurants.

In conclusion, lenticular could tap into the 3D trend, but it’s currently a very niche business. It seems to be open to the sort of benefits digital print can provide, but anyone adopting it would have to be prepared to put in plenty of effort, both on the technical and sales side.

Digital Printer Magazine - march 2010 - www.digitalprintermag.co.uk