Holograms are Dead, Long Live the Holograms!

Few overt security devices have been deployed as widely and successfully as security holograms – or DOVIDs (Diffractive Optically Variable Image Devices), to be more precise and inclusive. From banknotes to ID documents to brand protection, holograms have been a stronghold against counterfeiting for over 40 years. We’re so accustomed to them that we’ve hardly noticed the influx of global suppliers offering their versions of holograms not only to the security industry but also to the packaging industry. This has come with a price, namely the loss of some of their magic and exclusivity. So, after decades of loyal service, are we now witnessing the death of security holograms? We strongly believe that is not the case. But before we make the case for DOVIDs retaining their place in an arsenal of effective anti-counterfeiting measures, let’s take a brief look at the intriguing evolution of security holograms.

The transition from craft to science

Until the mid-1980s, holograms were mainly large format 3D images used as one-shot artistic media for communication purposes. The security sector only began to take an interest in the second half of the 1980s because of the high technicity required to both originate and manufacture holograms. Still, up to the early 1990s, security holograms were frequently based on the same traditional analogue recording of interference patterns of laser light beams, with physical objects as models to be recorded. The principle was to create surface relief patterns that would diffract light in a controlled manner which could be replicated in high volume on a medium such as film by means of pressure and temperature or, sometimes by casting a UV-curable lacquer. The origination process was then a delicate mix of science and craftsmanship, with the latter slowly giving way to the former. Manufacturing techniques were often borrowed from other industries (electroforming, vacuum deposition of thin coatings, gravure coatings etc.) and integrated into new, complex processes, thus raising the bar for counterfeiters. Eventually, in the 1990s, digital technologies mostly displaced the classical laser laboratory, where ‘scientartists’ shot holograms under a dim red light. Holograms could now be originated with computer-generated images of interference patterns with pitch and direction perfectly controlled. The holographer’s role shifted from craftsman to scientist and creative people were replaced by engineers and PhDs.

With the increasing power and accessibility of computers, technologies like e-beam, stereolithography, micro-recombining, and direct engraving were applied and adapted to create holograms – or, more accurately, periodic structures which affect the direction, amplitude, and frequency of incoming light beams. These structures could be integrated into a single master and then mass-replicated on a flexible medium. Like most successful products, the technology behind holograms has generated a plethora of ‘spin-offs’. Some of these have worked well in the security industry, others not so much.

Losing the reputation

Digital technologies opened a gateway to increasing the complexity of the security features. They also enabled a simpler, more industrialised origination process. As a result, holograms became very sophisticated, while the tools to produce them became more accessible. At this point a clear separation emerged. The established hologram manufacturers focused exclusively on the security industry and pursued a strategy of integration, R&D, innovation, and technological development. Conversely, a constellation of new players capable of originating basic forms of holograms attempted to capitalise on the most accessible technology to commercialise their products in both the packaging and the security industries.

And the result? This divergence distorted the perception of security holograms and gradually impacted their reputation. Holograms were, and still are, seen as commercially available. In fact, the class name ‘holograms’ was now too narrow a label to properly describe all the diversity of technologies employed by the various players. The manufacturers of the most advanced holograms reacted in two ways. They distanced themselves from the label ‘hologram’, which was now being steadily attacked by competing technologies with more exclusive origins. They also pursued increasing visual complexity as one of the differentiators.

However, since holograms or, more accurately DOVIDs, as overt features were meant to be immediately recognizable, even by the untrained eye – excessive visual complexity was an issue. By introducing very complicated animations, tiny elements, and optical effects visible under a narrow viewing angle, holograms became increasingly difficult to decode for the average person. In comparison, competing technologies, like colour-shifting inks, provided a more binary, straightforward response.

A new hope

In recent times, some of the major players have pertinently gone back to the basics: holograms need to fulfil two main functions, being difficult to counterfeit, and being easy to recognize and authenticate. Perhaps we should really start referring to security holograms as DOVIDs at this point, even if the term may now be once again too narrow to properly describe all the involved technologies. With advances in technology and consequent investment in R&D, the top manufacturers have succeeded in keeping DOVIDs relevant to security by:

• Expanding the capability of recording many types of surface structure, which was not achievable with traditional holography methods based on interferometry

• Playing with vacuum-coated materials

• Pushing the limits of manufacturing processes

• Bringing more weight to the design aspects of origination and manufacturing, resulting in visually appealing and eye-catching effects describable in few words.

Ultimately, they gave new life to DOVIDs by proposing new optical effects that are simpler to understand without compromising the intrinsic security level. However, this has been possible only by mastering all involved technologies, leveraging that capability of finding, borrowing, integrating different technologies and merging them into proprietary know-hows, that has always been a crucial skill.

What’s in the future for DOVIDs?

The pressure on holograms has ramped up again recently thanks to some new competing technologies, like micro-optics and magnetic colour-shifting inks. These technologies have shown that alternatives may exist and may even fulfil some expectations better than DOVIDs. But just as it seems that holograms belong to the past, we see that the fruits of continued R&D are again ripe for picking.

Two current directions are particularly interesting. The first is the exploration of new types of structures with dimensions in the nanometric scale or in the tens of microns. For comparison, traditional holography is typically in the range of tenths of a micron and shapes that are mathematically calculated to produce the desired optical response both in reflection and transmission. The ability to compute and then shape structures in custom ways has now become key to finding new visual effects that will define the next generation of DOVIDs. The second direction combines different technologies into the same feature. That could bring together the advantages of both technologies, ultimately giving the untrained eye one focal point instead of many. For instance, having a DOVID coupled with a micro-optic element, or with a colour-shifting ink, being seamlessly part of the same design and feature. This means a single application and a single expense for the final customer. Finally, as hologram manufacturers continue to borrow, combine, and adapt technologies from other industries to meet security needs, we expect to see a constant evolution of the products based on DOVIDs, something that is another crucial asset in security: being able to stay ahead of counterfeiters!

Ultimately, the key success factors for DOVIDs lie in their manufacturers’ spectrum of capabilities. The ones with deep theoretical and practical knowledge of design, mastering, thin film deposition, foil manufacturing and other crucial elements, will be the ones who will lead the game from now onward.

Are security holograms dead?

New overt features based on disruptive technologies do not come along very often, and the evolutionary nature of DOVIDs is still a major asset for the security industry. Let’s not forget that this industry has heavily invested over the years in applying holograms to banknotes, documents, and all kinds of media; that investment can and should still be put to good use.

We may have witnessed the end of traditional holography in the security printing industry. But given the capabilities some of the top players have developed, we don’t think the underlying technologies are on the way out any time soon.

Is the security hologram dying? Probably just in the name.