Lenticular printing is a process to create a multi-image impact from at least two existing images, and combining it with a lenticular lens. This process can be used to create various frames for a motion effect, offsetting the various layers at different increments for a 3D effect, or simply to show a set of alternate images that may appear to transform into each other. Once a group of images are collected together, they are flattened into individual, different frame files, and then digitally combined into a single final file in a process called ‘interlacing’.
The 3D effect seen in lenticular printing is due to the parallax (difference between the object viewed by left eye and right eye). In this process, the 3D image is portrayed onto a 2D printing surface. It is a special technique used to give an illusion of depth, width, height and a continuous movement of images.
Lenticular printing: New bizarre of printing
The long thin lenses are lined up with each image interlace, so that light reflecting from each strip is refracted in a slightly different direction though the incident light is in a single direction. The end result is that a single eye or camera looking at the print sees a single whole image, but an eye or camera with a different angle of view will see a different image.
The interlaced image is generally printed directly to the back (smooth side) of the lens. These sensitive thermoplastic material sheets are made of APET, acrylic and PETG as well as other materials. While PETG and APET are the most common, other materials are becoming popular to accommodate outdoor use and special forming due to the increasing use of lenticular images.
UV-cured inks are generally used in the process. These are free of VOC and dry very quickly by direct conversion of the liquid ink to a solid form, rather than by evaporation of liquid solvents from a mixture. Powerful (400W per sq in) UV lamps are used to cure the ink rapidly. This allows lenticular images to be printed at high speed. The mercury vapour lamps are the most common, which emit UV radiation in a broad spectrum and provide optimum curing. UV light with wavelengths between 100 and 380 nanometers is used to cure the ink.
UV inks are also much better to use for digital printing because the inks used in the other types of printing contain pre-polymers, which are equivalent to resins. The monomers that are used in this for polymerisation (which helps in the drying of the ink) contain many toxic, volatile, or smell bad compounds in it.
Long thin lenses
The application of digitally printing lenticular is available on few UV printers, out of which one is JF Series from Mimaki. This series makes it possible to produce a lenticular sheet. Coupled with the freedom to use any Flip /3D software to create customised image, this machine gives full authority to the users. The additional option of ‘white ink’ sharpens the image quality. And with the ‘clear coat’ option, a highly glossy finish print is obtained.
There has been spur in the demand for lenticular and very recently Rays 3D Motion Print, Mumbai successfully executed a great job for the banners of Yash Chopra’s Rab Ne Bana Di Jodi printed on Lenticular sheet of size 4’ x 8’ using Mimaki JF1631 supplied by Apsom Technologies, who are providing complete lenticular printing solutions.