So that security is not compromised, it is essential that such protected materials are not available widely and that supplies are limited to bona-fide security-related printers and converters only. In order to achieve this objective, recognized and trusted suppliers of security materials and substrates will endeavor to ensure that such security materials are only made available to trustworthy converting partners within the industry.
PROTECTION FOR NON-ORGANIC PACKAGING MATERIALS
Initially, this article will focus on non-organic materials that are used for packaging applications.
Metals, in the form of aluminum and tin plated steel are the primary materials we are dealing with here. Both are inherently difficult to secure (in raw material form) since they are not able to carry easily accessible markers that would be useful in assuring provenance. Therefore most security features need to be added further down the supply chain in the form of labels, inks or serial marking placed using inkjet print heads or laser engraving.
The one notable exception to this theme is the use of holographical, decorative and security embellishment to the raw material that can be applied before it is converted into cans or box format.
Holographic designs can be applied using a laminate or varnish onto which the optical effects are engraved using high definition shims and very heavy pressure. This gives the material a diffractive finish that can be formatted to provide a continuous image that delivers similar effects to those seen on elementary holograms (see Figure 3.1).
Figure 3.1 - Holographic effects can be added to metal based packaging in order to enhance its appearance and supply a high degree of surety that the pack is genuine
Metal is also a major component in securing metal closures on bottles and jars, mainly to seal in the contents and prevent leakage during transit but also to ensure that tamper evidence is built into the opening system so that a user is assured that the container has not been refilled or the contents tampered with.
There are various types of tamper evident metal closures, the most familiar being the ‘Crown’ cork. Others include a screw closure that incorporates a tamper evident band that is held in place by a perforation in the metal near the foot of the closure. When the closure is opened the perforations are broken and the released metal band can be seen to leave a visible gap between the top and base of the closure.
Because there is always a major risk of high value beverages and spirits such as whisky and brandy being attacked through refilling or dilution assault, it is also possible to add non-refillable systems to bottles and these are usually fitted in conjunction with the tamper evident metal closure.
Such non-refillable systems consist of a one way value which operates with a specifically designed pourer to stop product dripping down the neck of the bottle. Non-refillable systems are fitted in such a way that any attempt to remove them results in breakage to the bottle.
Figure 3.2 - Various tamper evident non-refillable systems exist. Picture- Guala Closures
It should also be remembered that metal is the most widely used material for the twist off lids used on glass jars. Tamper evidence on these components is delivered through vacuum sealing the container after filling and installing the closed twist cap.
The vacuum draws down the closure and allows for a ‘button’ mechanism built into the closure to remain firmly in place when pressed. In this form the cap is safe as the vacuum is only released on opening. After opening the button moves up and down when pressed and provides an audible warning. A message on most closures advises to ‘reject if button clicks on pressing’.
Metal, such as aluminum in thin rolled form, is also used as a lidding closure although metalized polyester type products are more popular in food and drink applications since tamper evidence is obtained through the use of heat sealing the film to the container to form a protective bond that guards against tampering and keeps the product fresh at the same time. It is possible to produce both these materials with a difficult to copy optically variable design that offers the twin benefit of tamper detection and authentication through the application of one device.
The combination of such films with blown or vacuum molded containers can also be seen in use for protecting non-food items such as printer cartridges and engine oil packaging. Both products are vulnerable to counterfeit and refilling attacks.
Finally, metal is a material that lends itself to rolling and tactile forming so that cans may be produced. Special opening mechanisms such as pull caps and the traditional use of a can opener make these components pilfer proof without further need for elaborate anti-tamper features.
The other inorganic packaging material that is difficult to protect at base level is glass. It should be recognized that glass containers can be colored and formed in many shapes and sizes and this requires a high degree of skill and expensive plant and equipment which is generally outside the reach of most counterfeiters.
For this reason most glass vessels of individual design, such as perfume bottles (Figure 3.3) and such like are relatively safe from the attention of copycat attacks. This does not mean to say that they are safe from refilling assaults though.
Figure 3.3 - Examples of individually-designed perfume bottles
However, generic glass bottles such as those used in the wine industry are easily available either as in empty or previously used and discarded format, or new from a crowd of suppliers.
In these cases it is necessary to protect vessels from refilling with shrink sleeve cap seals and to add primary identification markings in the form of laser engraving or by adding further security features in the form of labels or cap protection devices, more of which will come later.
A further point worth remembering is that many injectable medications are packed in glass vials (Figure 3.4) and these too are at risk from tampering and re-filling. A wide range of tamper proof and tamper evident sealing closures are also available for ‘at risk’ applications such as these.
Figure 3.4 - Injectable medicines packed in glass vials
PROTECTION FOR ORGANIC PACKAGING AND LABELING MATERIALS
The use of organic materials such as paper, board, plastics and more recently organically derived polymers and synthetics form the most widely used materials in packaging and labeling applications.
This material is by far the most popular for labeling applications because it is economic and can be easily transformed into labels.
Paper is easily printed and can be converted into both wet glue and pressure sensitive format in a variety of styles such as sheets, rolls and die-cut packs for onward automated application to containers, jars, cans and bottles.
Furthermore paper is endlessly flexible inasmuch as it may be manufactured in a range of colors and finishes and can be combined with other materials in order to provide decoration, instruction and of course security.
A further benefit of labels in paper format is that they are not robust enough to survive refilling attacks, since they are easily degraded and destroyed during attempts at removal, either before recycling or for re-applying to containers or bottles of fake product.
Paper is also the most trusted of materials since it is extensively used for high security print products such as passports and currency.
Therefore it should be no surprise that security labels manufactured from this resource mimic many of the safety features found in paper money and traveler identity documents.
The most predominant security feature that is used in security paper is the watermark. This feature is added to the paper at the ‘wet end’ of the papermaking machine and through the use of a specially constructed meshed roller the fibers in the wet wood-pulp are arranged into a form delivers a mono-tonal image that can be viewed in transmitted light.
The most commonly used process to make watermarked paper is the Fourdrinier process and the distinctive marks are formed by wires in a cylinder known as a ‘dandy-roll’. Because papermaking is such a complex operation and requires high investment as well as highly skilled operators, adding security features to the material is an effective method of thwarting copy attacks since these economies of manufacturing scale are not easily available to the counterfeiter.
Figure 3.5 - Schematic of a Fourdrinier Paper making Machine
Furthermore it is also possible to add distinctive marks, similar in appearance to watermarks at the calendaring end of the machine where mineral coating with various types of clay takes place which seal the paper ready for printing.
Specialist papermakers have offered this alternative to a traditional watermarks since Fourdrinier marks are not very clear in non-transmissivity, such as when used on opaque packaging surfaces.
A further benefit of applying embedded security markings at the calender stage is that the images become even more pronounced when exposed to UV light. This feature adds a further security benefit to this alternative process.
The most secure method of watermarking paper is obtained by using the cylinder mold made process. This technique is considered to be more secure than the Fourdrinier process as it is much scarcer in terms of producers and provides a much finer degree of tonal detail to the watermark.
This is why the process is preferred for the production of passport pages and the raw material for paper currency.
Watermarks created using the cylinder mold process are also highly visible in reflected light so they can be easily recognized when they are used on labels that will be applied on solid, opaque surfaces such as dark colored glass, metal or plastic.
Mold made paper, with accompanying watermarks, can also be lined onto pulp or paste board used for carton manufacture and subsequently utilized for pharmaceutical boxes or in cosmetic and perfumery packaging.
Figure 3.6 - A mold watermarked paper lined onto a pasteboard carton provides good visibility in reflected light
Watermarks may be placed in discrete register with labels so that they always appear in the same position or alternatively they can be incorporated in a continuous band in line with the machine direction of the web.
If discrete watermarks are chosen as a method of securing the material then the sheet will need to be registered with the print during the set up process on the printing press.
If a continuous web of material is being converted, as you would expect for roll label pressure sensitive production, it is necessary to fit a web guiding and register device to the printing machine in order to keep the mark in constant register with the printing web.
Established suppliers of pressure sensitive watermarked label material will be able to assist with the design and placement of a watermark on a self-adhesive substrate. Since discrete personalized watermarks can be expensive to originate and material will only be supplied in volumes high enough to set off the costs incurred with setting up a papermaking machine, it may be more practical to adopt a ‘stock’ design for shorter runs.
A number of alternative security features can be added to paper in order to check its provenance and make it difficult for counterfeiters to copy.
In its raw wet pulp form the material is fluid and it is possible to add visible and invisible ‘markers’ to the substrate at this time. Markers can take the form of colored fibers, small polyester disks (planchettes) or microscopic hi-lites. The latter are UV light reactive particles that shine like stars when irradiated with UV light.
Fibers can be added in various colors and at various lengths so that they can be observed on the surface of the substrate either by looking for them with the unaided eye or by exposing them to UV light. Measuring the length, distribution and color of these fibers allows for an individual ‘fingerprint’ to be embedded in the material, thus making it almost impossible to replicate by anyone wishing to copy this security feature.
It is also possible to embed narrow, two or three millimeter wide, security threads made from printed or metalized polyester in the security paper used for packaging and labeling requirements. Identical features can be viewed in banknotes and these threads can be deeply implanted in the material or made to alternate between the surface and interior of the paper in conjunction with the watermark (see Figure 9.1 on page 83).
There is also potential to add further security to these threads by applying coatings that react to thermal stimulation such as body heat from a finger or from friction through rubbing the surface of the thread.
Finally, it should be recognized that optically dull paper or board should be chosen for security applications where invisible UV security inks are to be applied during the printing process. This advice is applicable to inks that react to UV light and should not be confused with UV ink curing systems which is an entirely different process and used for drying inks and not for authentication purposes.
It will be discovered later in this training module, security paper used in conjunction with other complementary security devices, can be a resilient defense against both copy and tamper assaults.
Carton board for security applications consists of both pasteboard and pulp board. A slightly different approach is required when adding security features to these materials. Together, these substrates provide an excellent primary packaging material as well as offering a handy platform for important supply chain information such as route to market, manufacturing source and expiry data to be added.
Board products are also an ideal material for swing and hang tickets that can be used to provide useful guidance on a product’s capabilities, contents and size. In swing ticket and hang tag format both products can carry their own individual security features or be further embellished with security inks, foils or RFID labels.
Paste board, as its name implies, consists of a number of paper plies which are bonded together to form a thicker sheet that can be used to make boxes or cartons that protect products in transit and in storage before use.
These individual paper plies can carry their own authentication features in the form of forensic markers or more cost effectively offer a low grade security feature through mixing colors within each ply so that a ‘sandwich’ of colored material is created. Authentication is simply a matter of tearing the tag to reveal a colored core.
It is also possible to metalize board products so that they display a variety of colored shades and also to emboss the metal coating to deliver an optically variable image or holographic decoration, both of which offer certain low grade security devices by making the material difficult to replicate by scanning or by attempting to copy the design using publishing software and a desk top printer.
Figure 3.7 - Various colors are available to provide a quick ‘tear and check’ feature to check the provenance of a paste board swing ticket or tag
Other fraud deterrence techniques include surface embossing to create discrete patterns and film coating which delivers various optical effects.
At this point is worthwhile exploring some new and interesting technologies that utilize the surface properties of material at a nano-level to deliver an assurance that the material is original and not a fake.
Whilst these technologies are not per se print related they can be used to authenticate the very material on which the print resides.
This may be a label, a carton or a plastic container.
At a microscopic level each square millimeter of material is different. As an illustration of this fact a piece of paper is composed of millions of discrete fibers, all interlocked to form a continuous sheet.
If it was possible to ‘grab’ an image of say a specific square millimeter of the surface of a label – each label’s top right hand corner for instance – it would be observed at a nano-surface level that each was different and carried its own individual mat of fibers arranged in a dissimilar pattern.
Technology now exists that can record a ‘digital fingerprint’ of a predetermined, minuscule piece of material on every label, making it possible to identify the provenance of each one accurately. The process is also referred to as random feature identification since it allows items to be identified through the random changes that each item possesses at a microscopic level.
Sometimes these may be imperceptible changes in a letter of type – which will be addressed later – or imperfections in the material surface.
In biometric terms this technique is similar to the fingerprint recognition methods used by the police to identify suspected felons at a scene of crime.
A search for one fingerprint in a database of many millions takes time but this can be shortened through the use of complex software and high power computers.
Material biometrics works in a similar way but can deliver a positive or negative result much more quickly if the ‘fingerprint’ from the material is linked to a sequential barcode. This allows the barcode to act as an identifier and as a link to the surface material scan and its corresponding record in the database.
Various other methods exist that include the recognition of visible fibers randomly distributed in the material mat and laser illumination of the material’s surface and analysis of the reflected light from each predetermined area of a label. For speedy recognition both these methods also rely upon a barcode or other machine readable reference from which to match the image.
This whole fascinating field of material biometrics is changing constantly as imaging and computer processing and data management skills progress. Technology enablers such as cloud computing, smart phone apps and scanners as well as 4G communication systems are all conspiring to provide more on-the-spot identification methods for both the police and those investigators involved in brand protection.
Plastics and synthetics
These materials are very hard to protect from counterfeit attack. The best method of defense is to follow similar procedures to those used in glass containers; stylish, registered designs that are specific to each product should be considered since having to copy discrete designs and molded inlays can be restrictive when it comes to try to knock-off a particular brand.
This technique is not sophisticated enough to deter the determined counterfeiter though.
Further protection can be achieved through the selective use of micro-taggants which are uniquely identifiable particles embedded in base material and identifiable through proprietary readers or laboratory analysis.
Metalization adds a layer of complexity to films that can act as a barrier to counterfeit attack. Again this process is unlikely to discourage the determined counterfeiter. Opportunist attackers however will find it off-putting and may well try to experiment with an alternative target that takes less effort.
Metalization is mainly used as a barrier coating but also for decoration. In decorative form as will be discovered later, can be useful as a base for creating difficult to copy optically variable features such as holograms and high resolution multi-diffractive effects that are resistant to copy attacks and counterfeiting in general.
Tamper evident adhesives and tapes
Common usage in the labeling and packaging industry of the terms tamper evident, tamper resistant and tamper proof understandably lead to a good deal of confusion.
This is because these terms are used to describe a variety of similar functions that are designed to combat some very different threats or risks.
Tampering with labels to remove or mask fraudulent activity has been a threat ever since the introduction of self-adhesives over a half century ago.
The benefits that are available, for instance on removal of price marking labels, allow perpetrators to exchange the labels on low cost items for those carrying a higher price. This is why the majority of price marking labels carry distinctive cuts and indentations around their circumference.
Attempted removal leads to destruction of the label and immediate evidence that an attack has occurred.
Such benefits may be viewed as negligible now since price marking labels have all but disappeared with the growth of universal product coding and item scanning at check outs. Nevertheless this acts as an easily recognisable use of security cuts on a self-adhesive label.
Trends in tamper evidence
Tamper evidence has since evolved into a number of distinct forms, all aimed at protecting products from unwanted and often dangerous activity such as refilling, product spiking – which is linked to extortion attacks – and pilfering which involves taking part of the contents out of a sealed pack and then resealing it to conceal the fraud.
Figure 3.8 - Various methods of introducing tamper evidence to a container through the use of alternative label designs
Primarily the technology provides visual confirmation that a product that has been sealed has not been previously opened. This is achieved through the application of tape or a label over the closure or vulnerable points in the pack or at point of contact between the lid and body of the container.
However, as such tamper evident indicating products have evolved so have the techniques to compromise them.
Sophisticated stress-indicating materials and adhesives that are resistant to temperature changes are now being combined with authentication devices in an attempt to combine these essential functions.
The pressure sensitive materials industry has developed a range of ‘VOID’ substrates that separate when removal is attempted and the word ‘VOID’ appears when the top of the label is peeled away after fixing down. Otherwise a bespoke approach can be taken using a brand name that becomes tamper evident when opening a carton holding valuable goods such as a computer or smart phone.
Figure 3.9 - A brand name is revealed on opening this tamper evident closure
Other methods involve the use of specially selected traditional paper face stock with good resistance to tear. It is necessary to also have a good understanding of the packaging material that the tamper evident label will be applied to. Therefore it is often necessary to work closely with an adhesive supplier and the pressure sensitive adhesive supplier in order to achieve the best results of ‘initial tack’ and permanence. This is especially important where labels are being applied during an automated container filling process.
An alternative approach is to use ‘destructible vinyl’ face material for the tamper evident label construction. Vinyl face materials are high performance filmic products that are frangible on removal. Such products are utilized in heavy duty applications where resistance to moisture, heat, cold, dirt and grease would interfere or degrade paper.
Evidence of tampering is provided by the material itself fracturing into minute pieces as soon as removal is attempted. As removal involves a certain degree of ‘picking’ at the edges of the label the material fracturing becomes evident thus visually drawing attention to the attempts. Further security can be added at no cost by printing a solid colored border around the edge of the label making tampering even more evident.
By adding holograms plus track and trace technology, and in some cases RFID, these tamper evident devices will become an important component in future brand protection applications where anti-theft properties as well as protection from refilling and counterfeiting are important attributes (Figure 3.10).
Figure 3.10 - Tamper evident devices become an important component in brand protection applications
Sophisticated shrink wrapping films aided by specially marked tear tape and colour changing effects are now being combined with coding technology to protect bottles and similar containers from refilling, counterfeiting and dilution attacks. These take the form of shrink sleeves that are applied over the closure in order to provide protection and indication of first opening.
Developments in disabling RFID tags in an attempt to ‘kill’ them after a product is opened to prevent re-use also offers a dual tamper protection benefit to users.
Material science continues to make headway in this important area with a number of universities in the US, Europe and China now involved in researching and developing films and adhesives to meet the threats of the future.
Shape memory polymers
One further technology that is beginning to set foot in this market is SMP (Shape Memory Polymer). The material changes shape and form at specific temperatures thus providing an indication of authenticity and temperature change in the supply chain.
SMP materials can be converted into labels and tags and therefore provide a new range of opportunities for the brand protection industry as a whole.
Shape Memory Polymers are smart materials that have the ability to return to their original shape from a temporary state through the introduction of a trigger event – in this case heat.
Such label materials can be constructed to ‘store’ 3D shapes in the form of embossed text or logo’s and then programmed to release these when exposed to a specific temperature change, thereby creating unique massages that can be utilised as brand protection confirmations or specific safety alerts.
Figure 3.11 - Shaped memory polymers provide an authenticity check on neck sleeves and hang tags
The secret behind such materials lies within their molecular structure and their ability to change state rapidly when exposed to the correct trigger – in the case of the materials illustrated above this is 65°c.
Whilst some work is being done on triple shape memory materials that change shape and then revert back to their original shape after the trigger event, most SMP materials are irreversible after activation.
Since there is no need for specialist activation/authentication equipment the materials are ideal for consumer verification since all that is required to set the change in motion is a cigarette lighter or hair dryer.
It is too early to appraise the attributes of such a material yet but it shows promise in tamper protection when combined with the functions mentioned previously.
Forensic markers and taggants
Anyone who watches popular crime scene investigation TV and direct streaming programs will be familiar with forensic analysis that relies upon the principle that where we go we all leave microscopic traces of our passing along the way. This may be in a trace of DNA left on a cup or glass or a fiber from our clothes. These traces can be used in evidence should any of our misdemeanors be challenged or brought before a court of law.
Forensic markers and taggants are unique artificial and natural compounds that can be placed in suspension within a liquid or coated on to a solid object and even incorporated, at infinitesimal levels in the material used to make packaging and labeling substrates such as inks, paper, plastics and also, adhesives.
These substances consist of naturally available, but rare compounds that are mineral based or artificial organically produced ingredients that mimic DNA in their construction.
This topic will be revisited in more detail later in this study but at this time it is sufficient to know that many products today carry these forensic markers as a definitive measure in order to prove provenance and also purity.
In defining provenance we are referring to authenticity and a check against unauthorized copies being made. In terms of purity it should be recognized that where there is a risk of dilution attack, then covertly added ingredients that can be recognized in proportion to their mix, within a liquid or powder, are useful devices to measure unsanctioned dilution.
This measure is obtained through minute levels of taggant that are placed in (say) a liquid at a ratio of one part per billion. This is a quantitative amount so it should be present at all stages of the distribution system. If later analysis provides data that shows (say) one part per ten billion then it is provable that unauthorized dilution has occurred.
Likewise forensic taggants can be placed in inks, paper or board and then measured and recognized downstream in the distribution cycle in order to detect counterfeit products that may have infiltrated the supply chain.
It should be noted in passing that some sources claim that synthetic label materials are more easily recycled than their paper equivalents, since synthetic labels are separated during the recycling process and recovered for use in various polyolefin compounds.
Paper labels, especially those used on glass or plastic containers break down and create a mushy pulp that has to be sent to landfill.