Technology behind Hologram Stickers

The holographic technique was originally developed by Dennis Gabor for which he won the Nobel Prize in 1971. The method he innovated proved instrumental in improving the functioning capacity of electron microscopes and still very much in use in electron microscopy. As far as commercial exploitation of the technique was concerned, (for use in optical holography), it had to wait till the invention of the laser technology in the 1960.

The advent of laser technology enabled the making of optical holograms that recorded and stored 3D images. With the passage of time the manufacturing process became more and more refined. Nowadays, holographic labels and stickers are made in different formats-transmission holograms (holograms using rainbow transmission technology are the latest refinement), reflection holograms, and Specular holograms. Originally, the holographic method incorporated the use of high frequency lasers that were expensive but presently diode lasers are used for making almost the entire range of holograms.

The Holographic Technology:

The holographic technique makes possible the recording of a light field that is produced as the result of reflection of light rays from different objects. Thereafter the light field is recreated in the absence of the original light source or sources. The holographic technology is to some extent akin to the system of sound recording where the sound field produced by resonating objects (musical instruments for instance) is programmed in a manner for reproduction later on.

A hologram is made when a light flash light up a scene and the imprint on the recording medium is captured. Additionally, some part of the light beams called the reference beam must be directed upon the recording surface or medium. Lasers invariably serve as the light source for recording holograms and they must be of prescribed wavelengths. Much like the photographic procedure, holographic images have to be recorded in a dark room within a specific time frame (exposure time). The exposure time is monitored using an electronic timer that automatically beams the laser rays for a prefixed time period and then shuts it off.

A somewhat improved arrangement for recording and capturing a holographic pattern comprises directing the laser beam on the recording surface via a number of intervening mediums that alters the beam in various ways. A beam splitter is the usually the integral intervening element used to bisect the principal beam into two similar beams going in two different directions. An interference pattern results when two distinct laser rays falling on the recording medium intersect with each other. This pattern, which is embossed on the medium is the raw or unrefined version of the hologram design that’ll be ultimately printed on the sticker or label.

Of the materials that serve as the recording element, a highly concentrated silver halide film is extensively used for capturing images with a very high resolution.

VIkas Bhatnager is a professional packaging expert. Dealing with anti-counterfeit measures, he has been contributing posts on holography for Lasersec India that have been manufacturing different types of hologram stickers and labels (2D/3D stickers, aluminum foil stickers, roll-ons, holographic paper labels and so on) since a decade now.

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High Security 3D Holographic Stickers

Every year manufacturers spend a lot of money to produce goods and services with a hope that consumers would buy and appreciate them. On the other hand, consumers expect to get a total value for money. However, sometimes counterfeiters destroy this harmonious producer consumer relationship, thereby causing a loss to both consumers as he does not receive the promised quality of product, and the manufacturer as his brand image and revenue are crushed to pieces by the counterfeiter.

Counterfeiting is not a new phenomenon; it has been prevalent since the olden days. Easy access to technology and lack of measures on the part of manufacturers are some of the major causes of counterfeiting. However, with some smart moves the manufacturers can stay a step ahead of the counterfeiters and can facilitate the consumers with the high quality products.

Hologram stickers are a great way to put a stop to counterfeiting practises. Hologram stickers can be easily integrated into printing as well as packaging practises and have a vast field of application. E.g. manufacturers of passports, currency, toys, cars, credit card companies etc. can easily employ Hologram stickers to fight counterfeiting.

Holography is a process by means of which visual information can be recorded, stored and replayed in 3D (three dimension) form. While some holographic techniques are well evident to the human eye, there are also some machine read 3D holographic labels. While the former is most commonly used on products like books, cartons of milk etc.; the latter is used for high security purposes. Machine read holograms leave very little room for error and can be checked easily at the point of redemption or any random verification place in the market. They ensure a high degree of accuracy and are very effective in creating a safe and secure environment.

Whenever a 3D holographic sticker is held against light, a series of images become visible. Due to the property of “parallax”, twisting or turning the sticker in the presence of light, enables the observer to see a scene from a different depth and angle. This is primarily due to the presence of micro structures fused within the holographic sticker, which diffract the light falling on it.

Often, there are complex optical patterns on a hologram, which encode data about the appearance and depth of the photograph. These types of holograms require high precision optical instruments, lasers and other photo sensitive materials to create a master copy of the security hologram. Also, some holographic pictures can only be observed under certain special types of lights, which provide an additional level of security and verification.

3D holograms are extremely difficult to forge or reproduce as they are precisely duplicated from a master copy (highly difficult to create), by using complex as well as expensive machinery and tools.  Even the slightest tampering or scratching of holographic sticker destroys the infused image. The level of security of 3D holograms is well evident from the fact that passport makers, credit card makers, IDs, book publishers or even currency printers still employ them to avoid counterfeiting.

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