Digital Magazine

DOVIDs: Functional Beauty

One-of-a-Kind Cover
This month's very special cover is an obvious departure from PFFC's usual graphic approach — with good reasons. First, holography is a subject the editorial staff had identified over a year ago to “cover” in this issue. Second, while collecting information on this topic, we discovered there's plenty of basic information we could provide our subscribers for their reading pleasure and profit. And third, we wanted something special for our cover, considering that both holography and LabelExpo were this issue's main focuses.

As luck would have it, among a select group of companies involved in the generation and reproduction of optically variable devices (OVDs), Kurz Transfer Products LP offered its expertise and hot stamp foil materials to demonstrate the seemingly limitless possibilities a converter can offer its customers. PFFC's art director Michael Koch and I were challenged to communicate a graphic message, limiting our options for the final August cover design, to incorporate two OVDs among the many Kurz originates. We discovered how beneficial a close relationship among all suppliers can be. The August cover never would have happened if not for the project coordination of Tom Williams of Next Communications; the special expertise of Kurz' sales and marketing manager, security products, Oliver Moesgen; sales and marketing manager, graphic foils, Sam McElree; as well as Letterhead Press VP Dick Reindl and Hinderer and Muehlich's Don Wells. Our grateful thanks goes to them all.

Michael Koch supplied the artwork to H&M Dies to create custom stamping dies for the “celestial” central image (a generic Kinegram image originated by the Kurz design team) and the fanning spirals (a holographic wallpaper foil design called “Magma” also supplied by Kurz). The dies subsequently were shipped to Letterhead Press to hot stamp the images in two passes onto preprinted, sheeted PFFC covers, printed by Brown Printing, with a print-to-cut-registration tolerance of 1/16 in. Letterhead used two Kluge 14×22 EHD stamping presses, operating at speeds of 1,200 impressions/hr within a tolerance of 1/64 in. The finished, hot stamped sheets then were returned to Brown for binding and trimming with the remaining pages.

Kurz Transfer Products LP supplies hot stamping foil decorations in the graphics, plastics, cosmetics, consumer electronics, and appliance as well as many other sectors. Among the security products it offers are holographic foils, as well as other optically variable devices including Trust Seals (based on diffractive optics that can integrate unique, hidden security features) and OVD Kinegrams (used for the high security protection of banknotes and government documents). Charlotte, NC; 704/596-9091; 800/333-2306; kurzusa.com

H&M Dies provides micro-embossing and cutting dies to commercial and package printing industries. Charlotte, NC; 888/387-4226; hmusadies.com

Letterhead Press Inc. serves industries involving security, packaging (including folding carton and set-up boxes, point-of-purchase displays, and corrugated containers), business communications, publications, and entertainment. It provides fine embossing, foil stamping, custom bindery, die-cutting, folding and gluing, mounting, laminating, and holographic application operations. Waukesha, WI; 262/574-1717; letterhead-press.com

Brown Printing, Woodstock, IL; 815/338-0702; brownprinting.com
— Yolanda Simonsis

Through a combination of overt and covert means, Diffractive Optically Variable Image Devices (DOVIDs) offer a high level of security at a reasonable cost—and look good while doing it.

It is estimated counterfeiting, tampering, and theft affect 7% of world trade, equivalent to $960 billion of losses, and is rising at a rate of 15% per year. Of this total, the Global Anti-Counterfeiting Group estimates more than one-third, or $360 billion, is lost through counterfeiting.

With the use of color copiers and computer scanners, technology facilitates counterfeiting and drives the need for advances in document protection and authentication. The rapid rise through the 1990s in brand, product, and OEM counterfeiting extended the need for security to consumer and branded goods as well as to the recognized areas of banknote and document verification.

This led to the development of more sophisticated anti-counterfeiting aids, such as tamper-evident pack seals, overt/covert tagged labelstocks, UV/IR readable inks, RFID, and — today's most popular solution — OVDs: Optically Variable Devices.

Traditional security printing techniques are intrinsic to the product to be protected and can deter conventional methods of counterfeiting. However, newer electronic scanning and copying techniques require extrinsic devices using optically variable means of preventing forgery. OVDs include both inks and mechanical processes. However, the most widely recognized form of OVD, the “Diffractive Optically Variable Image Device” or DOVID, of which holograms are a particular class, cannot be copied by these electronic means and, therefore, are used increasingly in a wide range of applications.

DOVIDs have been used for years in decorative applications on packaging, gift wrap, and brand enhancement as well as for security. While for decorative or promotional uses, a strongly iridescent appearance is the primary requirement of a DOVID to provide consumer brand appeal, for security applications this is secondary. Production within a high security environment and ease of authentication are the key success factors.

DOVIDs aren't the only means of securing documents and products, but their ability to combine covert and overt levels of security with an attractive and obvious illustration of the fact — at reasonable cost — has given them greater growth prospects than other security devices.

Production Methods
There are five main techniques used to generate DOVIDs.

  • The simplest is to mechanically impress, or rule, grating structures into substrates, usually by micro embossing. This produces simple geometric structures and is used widely in packaging. The simplicity and limited optical variability restrict the use of these materials to less secure applications.
  • Dot matrix mastering requires the writing of diffractive pixels one by one onto photo-resist recording media by the focal overlapping of two laser beams. At the focal point, the two laser beams precisely overlap to create the desired microscopic interference pattern. By computer control, it is possible to draw images on the plate surface in a similar way to those produced by a dot matrix printer. This is a laser interference technique and not a holographic imaging technique. The resulting image does not provide true 3D effects. Its low resolution limits the application to non-critical applications.
  • Photo-resist interference lithography uses the interference pattern provided by lasers as in dot matrix imaging, but requires the expansion of the overlap area from a simple point to an area greater than the final image. By placing a series of photo masks containing different components of the image to be reproduced in close contact with the photo-resist plate, and by changing the orientation of the two laser beams, it is possible to produce a two-dimensional image containing multiple colors and kinematic effects.
  • Electron beam lithography operates in a similar manner to dot matrix imaging except that an electron beam is used to expose the plate. Greater technical flexibility and precision are available with this method but at the expense of speed, as greater time is required to expose the image. Higher resolution requires higher cost equipment and longer manufacturing time, and results in increased cost, limiting this application to high-end security devices such as micro lettering.
These techniques produce OVDs that are complex two-dimensional mosaics or patterns. Only classical holography using a split laser beam onto an object or computer-generated artwork produces true 3D imagery.

A powerful laser beam is split into two beams. One half is directed onto the object and the light scattered to be recombined with the second half of the laser beam, or reference beam, to produce an interference pattern that is recorded as an intermediate hologram, typically in high resolution photographic emulsion. The recording of light amplitude together with phases of wave fronts scattered by the object provides the perception of depth.

Combining this intermediate hologram or master to produce an image of the original object using a second reference beam suitable for recording a second hologram onto photo-resist plates provides the means of reproduction.

In practice, a high-security hologram may use many images or color components in different planes to provide the required levels of security. Careful design is needed to harmonize the iridescent properties with the 3D image of the classic hologram. This often results in the use of combinations of production techniques to provide the security levels and image generation specified.

The most common combination is dot matrix mastering with classical holography combining the two-dimensional kinetic and iridescent effects of dot matrix with the additional security provided by the depth perception and parallax only achieved by classical holography.

Classical holography provides 3D images of a unique object requiring any counterfeiter to have the same object for origination or access to the master. In a well-designed DOVID, there can be striking levels of iridescence with clearly differentiated color shifts. Alternatively, rapid shifts from one image to another are achieved by dual channel effects, or several images can be overlapped to provide multiple images to replay at different parts of the viewing spectrum. They are seen as image changes as the object is turned, providing a sense of movement.

Kinematic effects are produced by a series of diffraction gratings set to replay at a given viewing angle. Natural color techniques require sophisticated holography to mix a range of primary colors — a more sophisticated operation than straightforward photography.

Covert features include micro lettering and viewing the OVD or DOVID using laser to enhance and read discrete areas of the overall DOVID.

In all cases, the resulting DOVID is a collection of microscopic peaks and valleys on the plate surface, which are reproduced on the surface of a micro embossing roller using electro-forming processes. This is used to emboss directly onto polymer films or onto specialized coatings applied to polymer or paper webs. Then the webs are vacuum coated, usually with aluminum, to reveal the diffractive optical device.

Markets and Uses
In 2000, world demand for security devices totaled more than $24 billion, with tamper evident and tamper proofing representing 46% of this total, security printing 30%, and the balance being a number of lesser but more rapidly growing technologies.

It is estimated the value of applied OVDs in 2000 was about $1.3 billion, with growth between 27% and 30%.

The influence of these growth rates on the total market is a forecast world demand for all security products increasing from the current $24 billion to an estimated $36.5 billion in 2005, with OVD products at an estimated level of $4.8 billion.

Intelligent security labels and RFID smart labels using covert and overt devices but expanding functionality to incorporate traceability, product life, distribution cycles, and inventory management as well as security also are under active growth.

Now RFID (radio frequency identification) and magnetic technologies providing brand integrity from manufacture to point of sale are available at much reduced unit costs, encouraging wider use.

The market for OVD and DOVID products can be broken down into five main areas:

  • Banknote and High Security Foils
  • Document Protection
  • Brand Authentication
  • Brand Promotion
  • Others

The first three areas concentrate on security aspects of OVD and DOVID products.Security can be provided in several ways, depending upon the required level and end use.

High Security Applications
The worldwide traditional security printing market is estimated at $7.25 billion in 2000 and is regarded as mature, as banknotes, bonds, checks, etc., come under pressure from electronic trading and automated payment systems.

Lottery tickets, retail vouchers, etc., requiring security features provide high growth for this area, but don't necessarily involve vacuum coatings (with the exception of specialized color shift pigments).

Banknotes impose severe performance criteria on DOVIDs. In addition to the obvious requirements, DOVIDs on currency are required to remain durable under a range of conditions — resistance to crumpling, attack by solvents, sweat, mechanical damage by scratching, biological and industrial washing processes, bleaching, etc. — and must remain functional as security and design elements throughout the entire life of the note.

The first DOVID security devices appeared on bank notes in 1989, and now are used on around 180 denominations in more than 40 countries. In Europe, OVD use in bank-note production not only is increasing, but the number of notes showed dramatic increases as certain member states prepared for the launch of the euro currency in 2002.

Following steady growth in the 1990s, the decision to use OVDs and DOVIDs on all euro banknotes provided exceptional demand in 2000 and 2001. Each year required production of 7.25 billion euro notes of various denominations — 5.5 billion using a patch DOVID as a security measure and 9 billion using a stripe DOVID. This was equivalent to 14.4 million sq m at an applied value of $80 million and complemented the use of light-diffracting pigment in inks used to print additional areas of security on the new notes.

With an estimated note renewal and a top-up program of two billion notes annually post 2002, the European market size will have doubled over the euro's issue period.

The euro model presented positive encouragement to countries not involved in the euro — the U.K., India, Indonesia — to consider the device for their needs.

The eventual national currency converted; the manner of conversion (within the paper or as a stamping foil); the denominations converted (minor denominations require more notes); and the speed of change all will bear positively on the current growth rate of 30% for the years to 2005.

Costs of metallized and partially demetallized DOVIDs for banknote use range from $5.50 to $6.50 per sq m, averaging 0.9 cents per piece.

Document Protection
In document protection, a compound growth of 30% annually for the period 2001-2005 is realistic. It is believed this will involve the increasing use of demetallization technologies where a regular array of metal dots covering 25% to 50% of the surface provides a semi-transparent covering, or by the use of transparent, high refractive index, vacuum coating technologies (zinc sulfide, titanium oxide, etc).

The use of opaque, metallic coatings for these applications will be under pressure from transparent HRIC materials as the demand to apply security over variable information such as signatures, photographs, etc., expands within areas as diverse as driving licenses, ID cards, and passports.

The semi-transparent demetallized product or the high refractive index, transparent coatings are less obtrusive in these applications and can be placed over existing artwork, authenticating printed or handwritten data where insufficient space may be available for a solid DOVID. Including fluorescence in the adhesive systems used in conjunction with these semi-transparent devices can provide an additional level of security.

This area includes fiscal stamps where there is a noted growth in the use of OVDs and security foils for excise purposes.

The use of DOVID and OVD devices on tax banderols increasingly is common. In Russia between 8 and 10 billion alcohol tax seals are issued yearly. Hungary switched to DOVID use on tax seals after large quantities of earlier issue tax banderols were forged. The result: Forgeries fell from an estimated 24% of market volumes to less than 1%.

The use of DOVIDs on credit cards is well documented since the first use by MasterCard in 1983. For this application, very high abrasion resistance is essential. Restrictions on thickness means that a label or overlaminate cannot be used, and the only viable solution is a specially designed and engineered hot stamping foil.

Costs of demetallized or transparent high refractive index DOVIDs for document protection vary between $12 per sq m to $13.50 per sq m. Average unit cost is $0.09 to $0.25.

Brand Authentication
Brand authentication is an important application for security devices of all types — but again OVDs and DOVIDs offer unique combinations of properties, providing security and verification with excellent consumer-orientated design features.

DOVID use on computer software products is familiar to users of Microsoft products, and the need for such verification on drug and pharmaceutical packaging is self-evident. Tax banderols serve to raise excise revenues and to authenticate products.

It is estimated 80% of software in use in eastern Europe is counterfeit, and in Russia alone an estimated 12,000 have died from drinking “bootleg” vodka.

As one of the largest brand protection orders worldwide, the Turkish state-owned tea company, which produces 35% of Turkish tea, turned to holographic security following widespread counterfeiting. In the first year of introduction of holographically labeled packs, sales increased 13%, and in the first three years, the brand sold an extra 20,000 tonnes valued at $70 million.

Paper-based labels bearing holograms are used for authentication or as tamper-evident closures for all sorts of packaging. Developments include 8-15-mm-wide holographic stripes on rigid PVC shrink sleeves for bottle closures, providing heightened security and tamper evidence.

Devices may be overt or covert or a combination, depending upon product costs and level of security required, and can be included in the bar code providing product traceability with attractive security.

The cost of DOVIDs for brand authentication varies from $3.50 to $4.50 per sq m, equivalent to a unit cost of approximately 0.025 cents.

Brand Promotion
Diffraction and holographic patterns have figured highly over several years in product promotion and branding exercises.

Applications using 2-D and 3-D diffractive metallized films and papers as single-ply materials and as part of board or film laminates are common. Used at brand launches to rouse consumer interest, the materials include features to stimulate curiosity and differentiate the product from more conventionally packaged products. The products also are used to relaunch or repackage products. This may be to revitalize a brand or as part of product repositioning.

Specialized, in-register OVD and DOVID patterns have been featured on collectibles used as part of a marketing strategy. Canned soups and spaghettis have used holographic cartoon and action hero characters to promote a brand, often with the device hidden on the reverse of the label as part of the collection strategy. Baseball and football cards also have been the subjects of in-register holography to enliven the imagery.

DVD and videos have used OVD and DOVID as part of the cover designs, in addition to the use of a DOVID as part of the brand authentication on the actual product — a classic example of combining brand promotion and authentication.

Other Applications
A major use of simplistic OVD and DOVID is in gift wrap and counter rolls. In the publications market, metallized paper, metallized film laminates, and hot stamping foils incorporating OVD and DOVID are used to produce a range of effects from a hot foil stamped title to complex “in-register” printing. Security is not a consideration here, and the devices employed are less complex.

Whether as pigments to produce multiple rainbow-like prisms when applied as paints to metallic surfaces or within printing inks to enhance security; or as sophisticated holograms on banknotes and consumer goods; or simply as gift wrap, OVD and DOVID products are an increasing feature of everyday life and are set to grow at rates ahead of other material types.

Metallizing is key to today's advanced product authentication techniques, particularly DOVIDs and OVIDs. “Metallized Papers and Films: World Sourcebook 2002” includes an exclusive value chain analysis by key areas and more than 50 profiles of metallizing companies, raw material suppliers, and equipment sources. This 300+ pg. report is published by AWA Alexander Watson Assoc. and sponsored by the Association of Industrial Metallizers, Coaters & Laminators (AIMCAL). For details visit awa-bv.com.

Dr. William Llewellyn is an independent international business and technical consultant with a doctorate in chemical engineering. He is an associate of AWA Alexander Watson Assoc., an international market research consultant company for the converting and packaging industries.

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