Grafica News - April 2011
Special Effects In Screen Printing «A Golden Niche»
WHAT IS THE PURPOSE! AND THE TARGET ?
It is to catch suddenly and strongly the attention of the final user. It is to bring him news « sensations » from an AD product which can be of course printed or produced initially with different technologies, offset, digital and screen printing. This is obtained by the addition of some surface effects that will catch one or several senses of the user : first « the view » of course, ″ then, « the touch » by the feel of it « the smell » and why not, sometimes, « the ! taste »; ″ for « the hearing », it is quite rare, but some researches may bring this possibility. And of course, sometimes, several of those effects can be used on the same item, display, print and so on. It can also replace, often at a lower cost, some other technologies (hot stamping, doming, silvering, microembossing for ex.)
WHAT «ACTIVATES» OR MAKES WORK THOSE DIFFERENT EXCITING PRODUCTS?
It is interesting to know that they can be classified in different categories that belong to the principles of physics, chemistry or both combined…. The sun, some other sources of UV rays including « black UV », the temperature – warm or cold -, physical aggression such as scratching, dispersion, absorption and restitution of light, interference or incidence of light, reflection of some types of light, magnetism, the water to activate or to eliminate! The discovery of a different « process of activation » can bring you the idea of a special effect : that's how I had the idea to create special effect based on the use of black UV lamp, tube or spot to create safety inks for banknotes or passports (engendered by a Wood's lamp) and, incidentally, to use them as the starting point for these inks we studied and manufactured with Guy Massé at Dubuit Inks was based on some of those principles used for security, but here adapted to POP.
HERE ARE SOME OF THOSE SPECIAL EFFECT INKS AND VARNISHES :
PURELY VIISUAL EFFECTS : Gloss, Satin or Mat varnish, Fluorescent ink, Glitter ink and varnish, Hammer effect varnish, Mirror inks, Tilt effect inks, Liquid Silver inks, Metallic inks, Pearlescent inks, Daylight Active (Photo chromic) inks, Luminescent inks (reversible), Security inks (reversible) and their POP applications, Heat activated inks (thermo inks) - Reversible, Thermo black inks (non reversible above 60°C), Fading inks (non reversible), Just add water (definitive image once «!revealed!» = non reversible), Water removable inks (tattoo and other applications) – non-reversible,
VISUAL & TACTIILE : Structured varnish (visual and tactile), Abrasive inks,
TACTILE EFFECTS : Tactile varnish (sticky & texture), Tactile varnish (egg scale texture),
EFFECT THROUGH SCRATCHING :(to remove or to smell), Rub removable inks (Scratch), Rub removable inks (Scratch and sniff = perfumed inks)
PHYSICAL EFFECTS : Ferrous inks (ink for magnets), Ferrous inks (ink for magnets), Blackboard inks (visual,, tactile,, physical)
And Guru's 'SPECIAL' prescription: Of on the same image or item, several of those effects can be combined. But how to combine these effects with images printed with other technologies ″ Think about that, of course, if you do everything by yourself including offset printing for example, or not, the whole of the operations must be integrated in a manner to be usable in the workflow of your production or in combination with the one of an external supplier. ! The main problem is of course the adjustments of registers, knowing, for example, than, in offset if each sheet printed simultaneously in four or six colours is perfectly registered, it can be some differences from one pallet to another. Despite any type of screen printing press can be used (including manual and semi-automatic), the best presses for that kind of work remains for me the cylinder press with automatic feeding, for reason quite often combination with offset, of speed, productivity and quality of result. And, for the same above reasons, the UV technology is also the best available one in the present and the future, both for technical and environmental reasons.
WHAT ABOUT PREPRESS ? If we speak about the image, it is clear that the file for the « special effect » films imaging or for the CTS technology must be planned together with the one of the original image. As it is quite often question of « spot effects », the register problem is crucial and requires a perfect control off the different elements of the image.. Don't forget that some special effects will have to be entirely « designed » or separated from parts of the original image : this means that either a studio or an individual that created the image and/or yourself are able to prepare the needed proper part of the file! : this is of course very important.
AND THE SCREEN ? If we speak about the screen, the choice of the fabric and of the stenciling technique are crucial.
It is of evidence that, if you need a very thick deposit of varnish or sometimes of ink, you will have to use a fabric that can be, in some occasions, from 10 to 20 or of 43, 68, 77 threads/cm… Or also in other cases, 120 to 150/cm…
Follow the instructions of the ink or varnish supplier. The stenciling - multi-coats with direct emulsion (difficult to control and to develop above a certain thickness) or capillary films system - is also very important : Braille, very thick varnishes, HD, big particles contents (pearl, sparks, metallic or abrasive effect inks) requires coarse fabrics and some times very thick stencils : and, in this case, the most simple is to use 250, 350 or even 500 ì capillary films screened (as sometimes in textile printing) either directly or through the help of « direct-indirect » technology with a direct emulsion coat in combination. Fortunately, many of the « special effects » can be used in UV with the very classical 140, 150, 165 fabrics, calendered or not and an as classical direct emulsion coating in thin coat.
Don't forget that 50% of the ink coat is determinate by the fabric and 20% by the stencilling system.
PRINTING ? TAKE CARE OF COMPATIBILITY
As those effect will quite often have to be overprinted on inks and/or substrates printed with other technologies (offset, digital printing, flexo, hot-stamping, transfers, etc.) a huge care must be token about this compatibility.
A simple example ? Even, for a simple high gloss spot varnish above a classical offset print, be sure that the offset inks are « over-printable » : this means that they must not contains any wax, or worth, silicones, or of course that the so classical « automatic powdering » has been eliminated by the offset printer through a careful automatic brushing.
I told you, the quantities involved are often very high. Cylinder press is certainly the best tool at a speed around 2,000/2,500 sheets per hour (in 50 x 70 and most often according to offset data, 70 x 100 cm. Here again, a part of the speed is related to the ink or varnish consistency, thyxotropy and rheology. And you need to know very well your technology and the way you use it.
The squeegee blade shore can vary between 55° and 85°, according to the substance transferred. The floodbar can be thin or thick according the above seen necessities.
Curing, as we are more and more and will be more and more UV, depends upon the type of UV ink of varnish and of the thickness of the coat : is useful to know that in UV systems, a varnish how thick it can be (even several millimeters), will cure easily and instantly.
For metallic inks or some other printed chemicals, it has to be tested and set at very different speed and light intensity for example!
Once again, you must know and master your technology.
SOME TECHNICAL PREPRESS DIFFICULTIES ?
Here, I simply think about the manner to make the files for the use of RGB inks revealed through the use of black UV light with Wood lamp. Just as an example of a new way of thinking required. Let us take the « Girl face » for Dessanges. Starting from the RGB image, you must first turn Red, Green and Blue, the colours you will have to print with those special RGB inks that, in addition, give White (and not Black as the subtractive inks CMY will give). That's an example of the first trap : you must think differently, as matter of fact, exactly the contrary than when you think CMY printing!: «!subtractive!», not « additive » and, worst use a « negative » of substractive. Only an apparent but quite logical paradox. But here 100%+100%+100% = …WHITE !
HOW TO SELL THIS TO YOUR CUSTOMER
Marketing remains a key issue : if no one knows what you are able to produce with the highest control and offer of those special effects, how will you make money with it ?
Crystal clear ! That's the key of your success and that is also the point where FESPA can help you with this fantastic « SENSATIONS » book. Just buy some of them for your company in a manner that you and each of your sales people can have one of them to show your actual or potential customers, and – eventually – have some to give to your best customers or their studios or creators to « give them some quite possible good ideas ».
We, at FESPA, consider this Big Book – the SENSATIONS portfolio as an « help » for our members to exploit this fantastic « Golden Niche » possibility : a nice tool helpful in any circumstances…
But only an help and a tool : the real work will be yours. On one hand to exploit the idea we or I give you - on the other hand, and mostly, to adapt those possibilities to the problems of your customers, but, and that's the most important, to imagine, create, manufacture and print a lot of new ideas and effects that can be yours and yours only And here, we reach now the last and ultimate point :
SUGGESTIONS TO THE INKS MANUFACTURER
In general, you are not a specialist of Chemistry and Physics… If I am, that is simply related to my background and my years of experience and work with the manufacturers, but this is may be not true for many of us in our field.
So, when you have what you think as being an « excellent idea » about an original and new effect that can be achieved through screen printing, ask one of your manufacturers if he have an idea and a possibility to manufacture the product you need : I am sure that companies such as Dubuit, Marabu, Naz- Dar, Nor-Cote, Sericol, Sun Chemical, VFP, Wiederhold, or many other smaller companies will have the technical ability to manufacture those products : be simply clear and precise about what you exactly need to answer to or even improve the desire of your final customer and I am quite sure that some of them can have the technical ability to manufacture the exact product you need.. This means that you must be «!imaginative!» in front of your customer… … And «!convincing!» in front of your supplier to obtain exactly the product, new or more classical, you need!!
AS A CONCLUSION, your destiny is in your hand ! In the right way of my belief, I think that if we – FESPA - and some of us can help you, the main decision remains yours – image makers or even better, « image improvers » - and yours only!!!
By Michel Caza, Howard Parmele Award Winner Ex-Chairmain ASPT, Past President, FESPA Board
As you know and in the frame of the huge FESPA campaign «IN SCREEN PRINTING, AS IN DIGITAL, BE IMAGINATIVE», we look for some «niche» of interesting and remunerating applications of our Screen Printing technology. We also know that, in screen printing, the purpose and the art is to transfer « something, almost anything » more or less liquid through our dear screen!!
One of the most interesting niche in the graphic and textile screen printing fields is the printing of «special effects» : our customers want something « different » from their competitors and are prepared to pay a fair price for that… Those effects are also, in textile printing, a precious tool for the textile screen printer.
The same customer that discuss each cent of a price for a simple high gloss spot varnish will accept a much higher price if we bring him a very special enhancement of his image.
I saw screen printing companies around the world that make their happiness and sometimes fortune in this specialty : in Poland, in Bulgaria, in France, in Japan, in China and here in India….
That is why FESPA in a huge effort for improving an idea born a few years ago in the German Association had been creating one of the « Sensations » of the FESPA 2007 in Berlin, four years ago already, through its beautiful and useful portfolio named … « SENSATIONS »!