FAQs


1. How many kinds of effects could be made from lenticular printing?

It could be broadly classified as

a. flipping - one image swap to another, sometimes completely different, image; mainly 2-3 views
b. animation - multi-views or frames that mimic motion
c. zoom íV images change in size from big to small, and from small to big
d. morphing íV one image changes incrementally to another image
e. 3 dimensional (with depth illusion) - further subdivided into:-
i. layered 3D - objects appear in different layer; traditional type without additional cost for set up
ii. real 3D - 3d object with round corners created by software; more time, effort and cost are required for production and not all graphic are suitable for th is type

2. Can we combine several effects together onto the same images?
It is possible to combine more than one effect together but you shall note particularly that there is some constraint on the result.

For flip, morph, motion and animation, the alignment direction of the lenses is flexible - it could be horizontal or vertical depending on your required applications. However, for 3 dimensional, lens must be vertically aligned so as to obtain the visual parallax of depth illusion.

In other words, flip, morph, motion or animation could combine freely with each other but if you wanted to have 3 dimensional as well, the flip, morph, motion or animation will become left to right changing as the lens must be vertically aligned for 3 dimensional. Less promising flip, morph, motion or animation will then be the result.

3. What is the maximum size of your lenticular sheet?
To cater for the requirements of different industries, we are currently offering two main types of materials, namely soft PVC and semi-rigid PET. The maximum size for PVC is 400 x 500mm or 16 x 20" approximately. For PET, our maximum size could be up to A2, that is 420 x 594mm or 16.54 x 23.4". However, t he maximum size is not equivalent to the optimal working size.

4. What is your minimum ordered quantity?
We don't impose any particular minimum ordered quantity to our clients. However, we do suggest our client to make at least 1,000 lenticular sheets to achieve the most economic production run. It was calculated based on our normal working size of 14" x 20" for PET or 16 x 20" for PVC.

For instance, for 5cm diameter PET lenticular 3d sticker, we could make 54pcs per sheet and thus our suggested minimum ordered quantity will be 54,000pcs, say 54pcs per sheet x 1000 sheets of our suggested minimum.

5. Will you accept order with quantity less than your suggested minimum?
Yes, but please be reminded that the most economic production run is always achieved based on suggested minimal ordered quantity. If your project is not big in scale, please contact our marketing staff for discussion, we will try our best to make it happen.

6. What is lpi of lenticular sheet? Which is the current market standard?
LPI stands for "Lines Per Inch" or "Lenses Per Inch". Generally speaking, high lpi is required for jobs that require high degree of fineness and low lpi is required for large format printing, such as poster.

The current market standard is 75lpi that can be used for most general applications. It could be used to make all kinds of lenticular effects. For specific applications, there also exists lens with other lpi, gauge and material.

7. What do you mean by orientation of change?
Unlike 3 dimensional, the flip, animation, motion and morphing effects could be shown up only if the cards are viewed in the correct direction íV we called it "orientation of change".

"Orientation of change" could be "up-to-down" or "left-to-right" depending on how the lenticular sheet is positioned by the lenticular maker.

For "up-to-down" changing, the tiny rows of parallel convex lens are positioned horizontally. Flip, animation, motion, morphing effects could be seen only if you rotate the image along the x-axis or you view the image from different up or down position.
For "left-to-right" changing, the tiny rows of parallel convex lens are positioned vertically. Flip, animation, motion, morphing effects could be seen only if you rotate the image along the x-axis or you view the image from different up or down position.

8. What is the difference between "up-to-down" and "left-to-right" orientation of change?
In general, "up-to-down" changing is preferred to "left-to-right" changing for flip, animation, motion and morphing as the image will be more clear and the ghosting will be less. It is because our left and eye see same frame, or view, at the same time for "up-to-down" changing image but it is not the case for "left-to-right" changing effect.

However, for some applications, especially POP, signage, poster, "left-to-right" changing is the only choice as passerby walk across to see the changing images but will not jump up and down to see the image unless they are asked to do so.

9. Do you have any inhouse design for our selection?
Most of our jobs are custom-made but it would be our great pleasure to support our clients in every aspects whenever they encounter problem or need help.

Please feel free to contact us by email 3d@knt.com.hk for more information.

10. Is the sample production stage necessary? Can I skip it?
We strongly don't suggest our client to skip this important step. Lenticular printing goes through a complicated process and your original artwork has actually been changed artificially before you could see the effect.

Moreover, good lenticular print requires particularly attention to details, skillful workers for pitch test, careful image positioning onto the lenticular sheet, and the result sometimes depends a lot on quite a number of factors, including at least the design, the color, the lens, the methodology and the experience of the manufacturer.

It would therefore be better to see the samples before mass production. In fact, the samples could also be used as a yardstick to evaluate the quality of finished goods and as means to protect your right when you have quarrel with your vendors about the goods quality.

11. Can I specify any particular frame as "front" and "side" view?
It is theoretically possibly but not technically possible to impose any particular view when you are standing at any particular position. There are two main reasons.

First, very high degree of precise positioning is required but the current technology is not sophisticated enough to guarantee the outcome.

Second, suppose there are two images, say A and B, when you see the image from different direction, the images will appear in a repeated pattern of ABABABABAB.... so it is not possible to see only A or B images on either left or right.

12. How many layers could you make? Can I specify its order by myself?
The answer depends on the type of lenticular effects you are referring to.

Scenario 1: Flip, animation, motion, zoom effects

We actually call each view as "frame" or simply "view" instead of "layer". Some makers will claim that they could make 12 frames whilst some other will exaggerate their capability by saying that they could make even 24 frames.

Actually, there is no fixed answer and nobody could tell you exactly how many frames could be made. The fact is "the more the frame you make, the less visible and brightness each frame will be.".

To achieve optimal result, our advice is to note the following most important affecting parameters before you decide how many frames you actually want to make, "the more does not mean the better."

a. the size of the changing area
It is the changing area but not the finished size of the overall lenticular print that is important. The size of lenticular print could be as big as A1 but possibly only a small area will show up the views changing effect

The rule of thumb is "the smaller the area, the higher the number of frames that could be made."

b. orientation of change
It could be left-to-right changing or up-to-down changing. Ghosting will appear more easily if the lenses are aligned vertically, or the required orientation of change is left-to-right, as left and right eye always sees different images at the same time.

In other words, the number of possible frames will be higher for up-to-down changing than left-to-right changing.

c. lens per inch (or LPI) of the lenticular sheet
The current market standard is 75lpi and has been enough for moderately acceptable lenticular outcome but if you wanted to have a better result. You could ask for lens with lower lpi. However, there is some tradeoff for doing so. The edge of graphic will possible become jagged or stair stepped, and words will become illegible.

More importantly, the cost will be higher as low lpi lenticular sheet will usually accompany with greater thickness so as to get the right focus on the flat side of the lenticular sheet.

d. the graphic itself
The number of visible frame will be smaller if they are totally different, esp. for flipping effect. Generally speaking, we suggest making three views or frames for flipping and, for effects required more than 3 frames, we would suggest animation, motion, or zooming so the visibility of the intermediate frames is comparatively less important even if certain degree of ghosting will result.

Scenario 2: 3 dimensional (layered) effects

You could specify the number of layers required but we don't suggest our client to do so under normal circumstances.

It is because the requirement will reduce the "scope of imagination" available for our designer who is supposed to the expert in the field. Moreover, lenticular 3 dimensional effect is artificially created with certain degree of imagination. It relies on the miniature lateral displacement among different layers to show up the effect. The more overlapping areas between different layers, the better the result will be. In fact, the number of layer is actually, to a certain extent, limited by your original graphic.

          Definition of Lenticular terms


Animation

It is one of the amazing effects of lenticular printing in which sequential images are put together through the process of interlacing. When angle of view changes, these sequential images will be seen one by one and the illusion of fluid motion will thus result.

Color leakages
It refers to the unwanted color, mainly yellow and black, when the image is flipped or viewed at different angles. This is the most common problem of lenticular printing, other than incomplete changing and ghosting. It happens because of the poor registration among colors. Unskillful or less experienced printers with obsolete printing machine are usually the sources of the problem.

Direct printing
The process that prints image directly onto the flat side of lenticular sheet, mainly by offset printing machine.

Flipping
The simplest form of lenticular effect that shows up two or more, sometimes totally different images, one at a time, when the angle of view changes.

Gauge
It is the thickness of the lenticular sheet

Ghosting
It is one of the undesirable results of lenticular printing. It is said to have happened when more than one frame are seen at the same time. More ghosting will be found in left to right changing picture as left and right eye always see different picture at the same time. Other influencing factors include

1.Inferior Lenticular sheet
The focal plan does not fall exactly onto the flat side of lenticular sheet because of inferior extrusion process

2.Lamination versus direct printing
If the focal plan of lenticular sheet is right, the layer of glue or lamination adhesive, regardless of how thin it is, will unavoidably shift the position of focal plan.

3.Design
Some design wil have more shadow than the other. In general, if the color contrast among differnt frames are high, the ghosting will be more serious.

4.Number of frames
Multi-views changing effect is mainly employed for motion and animation. It is because the higher the number of frames, the serious the ghosting problem will be.

Hologram
It is an advanced form of photograph that records image in three dimension. True hologram does not rely on binocular vision and the 3 dimensional image could be seen by naked eye without any visual aid or reliance on any binocular vision.

Strictly speaking, lenticular image and hologram are not the same as the former relies on the visual illusion created by a sheet of plastic called "lenticular sheet".

Interlacing
It refers to the most important process of image manipulation for lenticular printing. Each frame of the original file is sliced and cut into strips - the width of whcih will in turn be determined by the pitch of the lenticular sheet and the number of views changing required.

Not all strips will be kept. Instead, only "1/number of views" will remain and the remaining strips will have equal spacing among themselves. The rest will be removed and replaced by another frame that has undergone the same treatment.

All interlaced frames are merged together to form a "complete" picture but image could only be seen through lenticular sheet with carefully positioning between the interlaced image and the lenticular sheet.

Lamination
The process that applies image onto the flat side of lenticular sheet by means of either glue or double-sided adhesive.

Lenticular
It is an adjective used to describe the technology as the fo rmation of special effects requires a transparent plastic sheet called "lenticular sheet" - one side embossed, or extruded, with tiny rows of convex "lens" and the other side basically flat.

Source files are each undergone a special process called "interlacing". The interlaced images are then merged together and printed, or laminated, on the flat side of the "lenticular sheet". Through light refraction of the tiny lenses, special effects could then be seen on the corrugated side of tiny lenses.

Lenticular technology gets its name because the effects show up when light from interlaced images refracted by the tiny lenses of the plastic sheet. To view "flipping", "zooming", "motion", and "morphing" effects, you shall either view the images on the front side, or corrugated side, from different directions, or rotate the card with direction of lenses as the axial. For 3 dimensional, the process is no necessary as images will be formed automatically by visual parallax.

Lenticular effects
Lenticular effect is the visual illusion created by lenticular printing. It could be broadly classified as

Category 1: Dynamic
Flip - images swap from one to another when view angle changes

Zooming - size changes with respect to view angle

Motion - body position changes with respect to view angle

Morphing - two dissimilar objects transform seamlessly from one to another

Category 2: Non-dynamic
3D (Layered) - 3 dimensional with illusion of depth; objects displayed in separated layers

3D (real) - 3 dimensional with illusion of depth; objects could have round corner as what we see in reality

Category 3: Combined effects
3D + Flip - 3 dimensional with part of picture showing left to right flipping

Lenticules
Lenticules are the smallest element of lenticular sheet. It refers to the single row of cylindrical shaped len on top of the sheet. Without lenticules, the lenticular sheet is basically a sheet of flat plastic only.

LPI
It stands for "lines per inch" or "lenses per inch". It is the measurement unit for the pitch of lenticular sheet. The "lines" or "lenses" refers to the parallel strips of cylindrical lenses, or "lenticules", on the corrugated side of the lenticular sheet.

Generally speaking, high lpi is required for jobs that require high degree of fineness and low lpi is required for large format printing, such as poster. With strong collaboration and experience of our production, design and sales teams, we are capable to provide technical and professional advices proactively to our clients in every aspects of the whole project. The current market standard is 75lpi that can be used for most general applications.

Morphing
It is one of the amazing effects of lenticular printing in which two different objects, mostly similar in contour, is being transformed seamlessly from one to another.

PET
The most commonly used material for lenticular sheet because of its durability, stability and clarify. Its texture is semi-rigid and is suitable for both direct printing and lamination. PET is an acronyme of Poly (ethylene terephthalate) and is environmental friendly - one of the most important import requirements for European countries.

Pitch
It refers to the number of lenticules per inch (LPI). The standard is 75lpi. The figure gives us some idea of how many lenticules could be found in inch but the exact figure will vary from sheet to sheet and some from pallet to pallet. It is important to carry out the process called "pitch test" to find out which is the actual figure before printing as incorrect matching of lenticular sheet with the interlaced images will result in poor lenticular printing result which is named as "incomplete changing".

PVC
Its full name is Poly (Vinyl Chloride). It is the most popular material used for making lenticular in the past. Although it is partially replaced by PET currently, it still carries its special values as its softness and flexible texture render it particularly suitable to be used as garment accessories where bending or folding is sometimes unavoidable.

Screen angle
A photograph is a continuous tone (contone) image but, for real world printing press, colors are simulated by half tone screens. Four process inks, namely cyan, yellow, magenta, and black are the most common. Each half tone screen is comprised of a series of dot. To ensure less noticeable perception of the pattern. Each halftone screen is rotated and placed at some angle to the original image, which is called "screen angle.".

Conventional screen angle is Black (45 degree), Magenta (75 degree), Cyan (15 or 105 degree) and Yellow (0 or 90 degree).

Unique pattern called "moire" wil be formed when half tone screens are placed over each other but not all of these patterns are desirable for printing. It applies to both traditional CYMK and lenticular printing.

Viewing angle
The refractive index, pitch and curvature of lenticules define a v-shaped region within which lenticular images could be seen clearly. The angle of such region is named as the viewing angle of lenticular sheet.

Viewing angle is useful as it could tell us whether the lens is suitable for particular effect. Generally speaking, narrow viewing angle is always chosen for 3 dimensional effect whilst the wide one is more suitable for flipping, motion, animation and those dynamic images.

Nevertheless, it does not mean that wide viewing angle lens could not be used for 3 dimensional effect and vice versa. For 3d, the visual impact will be less promising if wrong lens is used. For flip, the wrong choice wil just affect the speed of images change.

The viewing angle of standard 75lpi is around 49 degree.

Viewing distance
It is the distance from which the lenticular image will be viewed. The estimation is important as it determines which kind of lenticular sheet shall be used as different lpi, say lens per inch, of lenticular sheet will have different optimal viewing distance from which the images could be seen clearly.

In general, the figure of lpi and optimal viewing distance is inversely related. In other words, the higher the lpi, the shorter the optimal viewing distance will be and vice versa.

The optimal viewing distance of standard 75lpi is around 0.15-1.8M whereas the viewing distance of lower lpi of 50 is up to 1-5M. Thus, the former is used for hand-held piece and the latter is mostly used for large format poster.

Disclaimer statement: the above definition shall be used for reference only. We do not guarantee the correctness of the information and so do not bear any responsibiity for any damage or loss arisen from the use

 

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