Holograms – What are they and how are they made?
ELTRONIS – Specialty & Security Printing is a hologram converter and as of 2015 an associate member of the IHMA (International Hologram Manufacturers Association). Since then our company has reached the processing capacity of more than 1 million units a day, with a total of over half a billion processed holograms so far, that have been integrated in various security documents or labeling solutions for the pharmaceutical industry.
Below we offer the origins of holograms, a brief explanation regarding their creation process and present the various types of security holograms and the features they can incorporate.
What comes to mind when you hear someone mention the word hologram? Many science fiction aficionados would probably recall certain scenes from their favorite movies, in which characters appear, as if from thin air, who can talk and respond to others, just like he or she were really in the room. However holograms are not purely the work of science fiction. As a matter of fact they are utilized all around us. There are holograms on most driver’s licenses, ID cards, credit cards and even the cash currency of some countries. Younger people can also find them laying around at home, as they are present on CD, DVD and software packaging, as well as most everything sold as official merchandise for authentication purposes. The origins of holograms can be traced back two centuries.
Back in the 19th century ingenious inventors have come up with a way to capture and store images on chemically treated paper. This has become known as photography and has revolutionized the way people interact with the world around them.
They appear like three-dimensional photos that have got trapped inside glass, plastic or metal. When you tilt a credit card hologram you’ll see the image of a bird flying inside the card. What makes holograms different from an ordinary photograph? A hologram is a cross between what happens when you take a photograph and what happens when you look at something for real. Like a photograph, a hologram is a permanent record of the light reflected off an object. However a hologram also looks real and three-dimensional and moves as you look around it, just like a real object. This is due to the unique way in which holograms are made.
A hologram is made by reflecting a laser beam off the object you want to capture. As a matter of fact the laser beam is split into two separate halves by shining it through a half-mirror (a piece of glass coated with a thin layer of silver, so that half the laser light is reflected and half passes through – sometimes called a semi-silvered mirror). One half of the beam bounces off a mirror, hits the object, and reflects onto the photographic plate inside which the hologram will be created. This is called an object beam. The other half of the beam bounces off another mirror and hits the same photographic plate. This one is called a reference beam. The hologram forms where the two beams meet up in the plate.
So how do holograms work? Laser light is considerably purer than ordinary light coming from a flash light. In a flash light beam all the light waves are random and jumbled up. Basically they run along like schoolchildren racing along a corridor at the end of a school day. A laser is the polar opposite of this. In a laser, light waves are coherent, meaning that all of the light waves are the same size and bend the same way. As a result they travel precisely, just like marching soldiers. When a laser beam is split to make a hologram, the light waves in the two separated parts of the beam are traveling in identical ways. When they recombine in the photographic plate, the object beam has traveled via a slightly different path and its rays have been disturbed by reflecting off the outer surface of the object. Recombining the beams shows how the light rays in the object beam have been changed compared to the reference beam. A hologram is effectively a permanent record of what something looks like seen from any angle.
Every point in a hologram catches light waves that travel from every point in the object. That means wherever you look at a hologram you see exactly how light would have arrived at that point if you would have been looking at the real object. So, as you move your head around, the holographic image appears to change just as the image of a real object changes. That’s why holograms appear to be three-dimensional. Interesting fact: every part of a hologram contains the image of the whole object. You can cut off the corner of a hologram and see the entire image through it.
In the 1980s scientists found a way to print holograms onto metallic film, thus becoming an incredibly important form of security. Today, holograms can be found on a wide variety of products. These labels are very difficult to forge, because they are replicated from a master hologram which requires expensive, specialized and technologically advanced equipment.
Security holograms are classified into different types, with reference to the degree of optical security incorporated in them during the process of master origination. Some of the security elements which can be incorporated are: 2D/3D hologram images; Dot matrix; Flip Flop; Electron-beam lithography, Guilloche pattern, kinetic images, micro- or nanotext, hidden images, watermark, switch effect, true color images, etc. Holograms can also contain laser-marked or printed serials in order to increase their security level.
The most commonly used hologram type are the 2D/3D hologram images. As a matter of fact, they are not holograms in any true sense of the word. The term hologram has taken a secondary meaning due to the widespread use of a multilayer image on credit cards and driver’s licenses. This type of hologram consists of two or more images stacked in such a way that each is alternately visible, depending upon the angle of perspective of the viewer. These holograms display a unique multilevel and multicolor effect, having one or two levels of flat graphics floating above or at the surface of the hologram. The matter in the background appears to be under or behind the hologram, giving the illusion of depth. All the above mentioned security hologram types are created with highly specialized sophisticated technology, making their forgery difficult and expensive.
Concealed images (seen at large angle light diffraction and at one particular angle only); hidden element (which can be detected only by using a special equipment); Guilloche pattern (set of thin lines of a complicated geometry drawn with high resolution; visual changes of color along each separated line); kinetic images (seen when the condition of hologram observations are being changed; turning or inclining the hologram allows the movements of certain features of the image to be studied); microtext or nanotext (they can only be observed by microscope) are harder to duplicate. True color images, include several security features combined, resulting in attractive, high-security holograms which can’t be duplicated, unless original photo can be obtained. This means that it is one of the best ways to prevent counterfeiters.
ELTRONIS offers various types of holographic labels with a large selection of security features, applicable in different industry branches. If you are in search of a custom holographic labeling solution, look no further, please don’t hesitate to contact us.
