Materials for the Production of Holographic Self-adhesive Stickers
I. Top Layer of Self-adhesive Sticker – Material and Thickness
Holographic self-adhesive stickers are produced by pressing into a plastic electroplate or transparent film. Acrylic glue is then placed on the basal layer (metallic layer) of the sticker. Holographic sticker therefore has 3 layers, and characteristics of these layers can be chosen according to your needs and intended application of this self-adhesive sticker.
Top layer of holographic sticker is made of a plastic film which is very thin and translucent. This film for printing of self-adhesive sticker can be made of OPP, PVC or PET materials. The most used material for holographic stickers is PET (polyethylene terephthalate) in almost amorphous form, which guarantees high transparency. All holographic stickers are normally produced on the basis of a PET film because this material fulfils all required characteristics almost perfectly. One of the unique characteristics is high resistance against wide variety of chemicals, mechanical strength, extremely high impenetrability of liquids and gases, low thermal dilatation and resistance against high temperatures which allows the lamination of holographic seals and also impress in laser printer (the melting point of PET is around 267 °C). Its alternative can be a material called - Oriented Polypropylene - which is used mostly as a wrapping material for its better pull strength. Therefore it is no used for a production of self-adhesive stickers but it is rolled to rolls as feature-length wrapping materials. Of course there are customer’s holographic motives all over the sheet which are repeating in cycles. There is no gluing at holographic OPP wrapping films. PVC joined with holographic printing can be used for special applications like a wrapping material for groceries (instant contact with the groceries). PVC film is known for its high mechanical expansion and therefore has to be combined with layers of other materials like OPP or PET to be suitable for a production of the holographic film. This kind of film can then be also used for a production of holographic periodical patterns used for wrapping.
Another optional parameter of a load-bearing film of holograms is thickness of the film. This information is not important for standard applications of the self-adhesive stickers and holograms are printed to PET film with the thickness of 67 microns. For your special applications of labels or wrapping materials you have an option of choosing the thickness of 20 microns. The price will be calculated individually if a customer chooses his own thickness. All prices listed at our website are calculated with the thickness of 67 microns of a PET film.
II. Middle Metallic Layer for Holographic Impression
The middle layer out of all 3 layers of the holographic self-adhesive sticker “sandwich” is a very thin metallic layer into which a holographic impression alone is transacted. Exactly this layer is a load-bearing medium for rainbow like passages creating pictures that are in your draft design. Top layer in a form of a plastic film gives mechanical strength to the sticker and protects the metallic layer from damaging.
Most commonly used is an aluminum layer which gives holograms a typical appearance of silver reflecting areas with rainbow like tones. Silver color of the base offers the most plastic, the most colorful and the most outstanding effects even when the light is very bad. The most perfect effects are achievable at the full daylight.
Apart from the most famous silver color of holograms you can also choose from other colors just so it suits your purposes. The color of a load-bearing film stays unchanged and a color-bearing part according to your choice will be borne by a layer of metal into which the hologram is printed. Apart from silver, amid commonly used colors belongs also golden, and for these most commonly used colors we have prices calculated here at our websites. You also have an option of a blue, green, yellow, and red color... A price for these colors of medias will be calculated individually with a concrete order.
The variety of possible types of colored films for the production of holographic self-adhesive stickers and wrapping materials.
Another possible look of self-adhesive sticker is translucent hologram on a transparent film. Pasting transparent hologram over a picture or a text does not affect its readability and does not look disturbing even though it is greatly recognizable and visible from other angles. More information about this type is written in section “Your Draft Design-Transparent”.
A technique of translucent holograms on a transparent film can be used for production of self-adhesive stickers and wrapping films.
III. Method of Demetallizing of Load-bearing Metallic Layer
After the manufacturing of holographic self-adhesive sticker is completed, which includes pressing of graphical items to load-bearing metallic film, the hologram itself is almost finished. It will contain as many layers as the method of its production allows. Another layer can be added to the draft design to enhance your design. In this layer it is possible to define the transparencies. From a digital processing of a picture we deal with one bite alpha channel. At a completed load-bearing metallic film with holographic relief, a photosensitive layer is applied. This layer is exposed to light through a template manufactured on a base of graphical layout of demetallized layer, the photosensitive surface is then chemically initiated to wash away the coping film from unlighted areas. After that, the holographic layer is oiled in an acid which outlines the uncovered areas of load-bearing layer. Holographic impression which should be visible are not influenced by this process, however, other areas are outlined and therefore stay transparent.
This method is usable no matter of previous preparation of hologram (single layered, two layered, with master...) and can also be used for numbering or text describing. This layer is always greatly visible and readable. By this method it is also possible to create translucent windows e.g. for visualizing of series numbers at which will the securing self-adhesive sticker be paste on. Demetallization is also used for a production of transparent holograms which should not cover the pictures at which they are stick on. Last but not least it is a method which allows to create a self-adhesive sticker with arbitrarily shaped edges – e.g. in a shape of a seal or a leaf with burned edges. Samples of this method are shown in this section Demetallized Security Self-adhesive Stickers on Stock.
IV. Self-adhesive Basal Layer
After hologram is pressed into metallic film on a load-bearing plastic film, the sticker is finished. In order to make a self-adhesive sticker, another layer has to be put on – the glue. On a basal metallic layer a very thin layer of a permanent transparent acrylic glue is applied.
An option of choice when designing your own self-adhesive stickers is in this layer represented by Tamper-evident or Void-evident technology. In these types of self-adhesive stickers, the glue is not applied on a whole area of hologram, but through the template with a specific pattern. When the sticker is removed, in those areas were the glue was not applied, the metallic film does not separate from a plastic film and the graphics that was used for a production of the template will not be visible. Stickers produced this way carry increased probability of unauthorized manipulation and react by a specific damaging of load-bearing metallic layer – exposing the words “VOID”, “ORIGINAL”, “Cancelled” or a regular graphical emblem (depending on a type of chosen pattern medium). It is clear right away that the hologram was removed even if just a little bit. Attempts to stick it on again will not change anything about the visibility of exposed words. This technology highly increases security value of a sticker because even if the seal was removed from a badly ungreased or a rough surface by potential violators, it will be changed by exposing the greatly visible words for good.
When ordering tamper evident self-adhesive stickers you can choose from above stated words or you can create your own graphics made of words or emblems. The choice of user’s pattern will, of course be financially more demanding than general usage of patterns from our menu.
|A1 - security self-adhesive sticker with VOID pattern||B1 - classic sticker with a destructive pattern|
|A2 - the sticker leaves VOID word as residues when peeled off||B2 - a remainder of a pattern after a classic self-adhesive sticker is peeled off|
|A3 - the remainder of a ripped VOID sticker||B3 - a remainder of a ripped classic self-adhesive sticker|
|C1 - colored sticker with a destructive pattern||D1 - security sticker with a square VOID pattern|
|C2 - aa remainder of a pattern of the colored self-adhesive sticker after the sticker is peeled of||D2 - the sticker leaves VOID word as residues when peeled off|
|C3 - a remainder of a ripped colored self-adhesive sticker||D3 - a remainder of a ripped VOID sticker|
V. Hot Stamping
Another alternative of gluing is so called hot-stamp technology – hot impressing of holographic stickers and/or labels. Instead of permanent glue, hot melt glue is applied on the metallic side. To activate the glue the hologram pattern is impressed with heat. The hot impressing of holograms allows pasting the holograms on paper and/or plastics, with an extremely strong connection to the surface. In addition, an impressed hologram does not stand out of the surface and becomes its very natural part. Hot impressing is normally done by the machines and that is the reason why the stickers are not organized in a raster but rather in a thin endless chain and this way the machine can unwind it itself.
Hologram sticker for hot stamping impressed on a stripe that is put into the machine.
VI. Adherence of Self-adhesive Holographic Films
We offer hologram stickers with strengthened layer of glue and higher adhesiveness suitable for more problematic (rough) surfaces. You can now use this option even in your custom designs of self-adhesive sticker. You can try the sticker with a higher adhesiveness from our store; more information found in Flip-flop Multi-layered Hologram Sticker. More information about adherence of the sticker is written in the next passage.
Normally, holographic stickers are made on a very thin PVC film, its thickness is about 30 micrometers. It is intended to produce a self-adhesive sticker that would be as thin as possible and therefore would not disrupt the surface on which it is paste on. This way it will not create a disruptive relief and its edges will not be too high. As the PVC film is thinner, the sticker is more resistible against intended and unintended removal – with this extremely low thickness it is not possible to peel off the sticker with the nail or a razor and it gets instantly and visibly damaged. The ability of the hologram sticker to be removed dictates its level of counterfeiting a very important and watched parameter. An important role here plays the layer of glue which is applied on the basal side.
A layer of glue that is used as a basal part of holographic self-adhesive materials cannot increase a profile of the sticker because of the reasons stated above and therefore this layer is extremely thin. For these applications high quality hydrogel glue is used.
To get an expected adherence to the surface after pasting on the sticker with the expecting results two important steps have to be taken into consideration. Please read the following steps thoroughly. Since this procedure is done usually by you please, keep these two important things in mind:
VII. Cleanliness of the Surface
Not even the best glue will keep the sticker pasted on a greasy surface. The hologram will act the same way on a greasy surface as it acts on a greasy sheet from which you peel it off before sticking it to the surface. In a case of paper or enamel ceramics you don’t have to ungreased the surface, but many industrial products come into contact with oils or lubricants during the production. This does not involve just industry, where a need of removing grease from the surface is evident. Even a simple touching of the surface before pasting the sticker can result in a decrease adherence with the surface, because our fingers tend to be unexpectedly greasy. Before application of the sticker on surfaces like these, we recommend using chemical agent for removing grease – thus a suitable dissolvent. It is inevitable to choose it the way that the surface of an object will not get damaged. As a completely universal and effective can be considered a pure alcohol or isopropyl alcohol – which does not have to be suitable for cleaning pure glassy surfaces because it could leave white marks after drying, just as roughly denaturized alcohol. Before applying the sticker on very greasy surfaces, especially industrial parts, we recommend using benzene. As completely unusable is considered diesel or classic petrol for combustion engines, applying of these substances is counterproductive. For metallic segments which came into direct contact with lubricants during the production is possible to use the most effective product for removing grease– tetrachloride. It is highly recommended to be cautious and protect your health while using it (use proper ventilation and eye protection). At the same time make sure that there will be no eventual contact with plastic parts of cleansed product – those would be immediately and irrecoverably damaged.
VIII. Structure of the Surface
Apart from cleanliness of the surface, the very structure is important. It does not really matter whether the surface is porous or not. Critical is whether the surface is smooth or rough. Glazed metallic surfaces chrome and glazed parts, smooth plastic or glassy surfaces create absolutely ideal place for pasting on the hologram because here it will adhere by its whole area. From places like these it is sure that it cannot be peeled off without damaging. In case of rough surfaces the constant of adherence will, unfortunately decrease. That, however, does not mean holograms cannot be placed on these surfaces because thanks to quality glue there is great back-up. As the surface is rougher, demands for removing grease increase. From microscopic point of view rough surface represents some kind of a “hilly land” and distinctly decreases the area on which the sticker will be paste. Because the layer of glue is very thin, the area used for pasting the stickers is only tops of those “hills”. If it is possible, we commend to glue an object or a product in a place that will be structurally most suitable for the best adherence (in a part of the most suitable material). A big problem could be a wooden surface lacking lacquer – here it is necessary to do a physical testing by pasting the sticker on the surface of the wood, since the wood surface can have different degrees of smoothness. Another option of resolving this is using increased layer of glue. You can use this option when designing and ordering the self-adhesive sticker according to Your Draft Design needs.
If you are planning to paste the sticker on a product that could have a problematic surface (according to what is written above), we recommend you to order samples first and try their adherence to the surface. Do not forget to order a Flip-flop holographic sticker along with the samples.This sticker has a much higher layer of glue so its adherence to rough surfaces is much better. You can ask for a strengthened layer of glue while ordering the self-adhesive stickers according to Your Design.
IX. Holographic Master
Holographic master is a name for original pressing forms for reproduction of holograms it is a deck into which an exact mathematically generated picture according to graphical draft designs of hologram is burned by laser. If you need to seal a lot of copies, also copies of the master have to be made. For sealing is normally used nickel stamping die – a nickel deck with a “printed” picture of a hologram. There are many types of holograms and in connection with that also multiple ways of pressing die production. The master can be produced by burnout with help of a coherent collimated laser light radiation directly on a glazed metallic deck. By this process a positive pressing die is directly produced. A more used method of using laser printing with much smaller capacities and therefore cheaper manufacturing with using the photo path – a glassy deck with a layer of photosensitive material, which is brought up by lighted/unlighted (positive/negative photo material) where the glass deck is lightened instead of a metallic deck. A master produced like this cannot be used for impression of holograms on cylinder presses and therefore a metallic copy of it has to be made. A glassy deck with holographic pattern is silvered by silver vapors. Consequently produced conductive layers are then used either for direct galvanizing by a nickel or for production of copies, with a help of so called electronic forming which results in a nickel deck impression. As many dies can be created as it is needed for a precise production according to desires of a customer.
X. Security Self-adhesive Stickers with Guilloche Graphic Item
Guilloche item is another graphic security application which you can use in your draft design of a hologram. It consists of thin corrugated lines which create ornamental patterns (rosette) for many known from their childhood game Inspiro. Complicated geometrical formations of guilloches are suitable for securing and decorating too. Typical usage is securing most of the state documents of high importance and mainly for preventing bank notes from counterfeit. Guilloche strings can be found in ID cards, driving licenses, arms licenses, passports, technical cards, highway stamps, reports, trade licenses and of course, on every paper means of payment. Especially paper money and bankable papers have been guilloched by many applications. Long time ago it was necessary to use resourceful mechanical machines using a similar principle to above mentioned Inspiro to create a guilloche. They carved thin corrugated lines into a metallic deck, creating complicated, multiple times crossing and immutable cyclic geometrical formation according to a mechanical setting of the machine. This stamping die is then used as a printing deck for primer printing of documents and papers that want to be secured. The higher safety level the thinner line, thicker line printing and more crossing used in the pattern.
Guilloche presents a good prevention against falsification by scanning, printing or copying. Individual lines of the geometrical pattern are damaged while scanning and followed-up reproducing and therefore consist of many disjointed points thanks to deficient discernment of scanning and also printing. Present numerical processing allows fluent and fast draft design of guilloche ornaments thanks to exact mathematically described curves and preparation for printing in unlimited discernment. The same way of imitation of security picture could be used when falsifying and that is the reason why software for generating guilloche patterns offers a function of making random mistakes in the structure of the curves. In some places of the line it turns aside from the mathematically calculated position on purpose and a forgery will differ in these abnormalities under the microscope. Apart from the function preventing from falsification and copying, a guilloche can have only a decorative function and gives respectability and authenticity to the documents. Above that, graphically unused areas get filled. The decorative patterns can be used as a draft design or frames of graphical items – rosette.
Custom Design of a Hologram or a Vinyl Self-adhesive Sticker with Guilloche
If your vectorial graphical application allows creating a guilloche pattern, simply blend it into one layer of the draft design. If you want to use guilloche draft design at your order, we offer you our own guilloche ornament as a pattern. The same way we are capable to create ornaments of this type, like a rosette rounded by graphical items added by you. All you need to do is contact us and describe your idea.
Example of guilloche design and a graphical item-guilloche.