Animate your audience

Part of making a great lenticular print is in selecting the right materials and processes for the desired effect, and seldom do two projects share the exact same concerns. The following information is nuts and bolts level stuff intended to guide those who want to know more about material options and the print side of things. Of course not every project requires this, nor is it always advisable, so if you simply need great prints with minimal fuss let Parallax Printing do the heavy lifting for you.

Types of Materials
Lenticular plastic sheets, commonly referred to simply as “lens,” come in three basic material types, PETG, Acrylic and Polystyrene. The overwhelming majority of lenticular lens made in the United States and Europe is PETG, which is a form of polyester and as such is very durable and long lasting. It is resistant to impact fractures and cracking and is a great choice for both fine art and commercial lenticular. It is slightly more prone to scratching than acrylic so care should be taken when handling. Acrylic (PMMA) is a very common everyday sheet plastic and some very high quality lenticular lenses have been made from acrylic resin. Acrylic is known for its clarity, especially when used in thicker sheet products. Though not generally considered brittle acrylic is prone to edge damage if dropped and is more difficult to cut than PETG. Polystyrene, or PS, is also a clear plastic resin suitable for thick sheet products, and is the cheapest of the plastics used to make lenticular. PS is very brittle and yellows quickly with exposure to UV, and is generally not considered a premium material for lenticular production. We use primarily PETG lens sheets in its day to day production though acrylic is sometimes used when a quality product is only available in that form. Do to its poor performance profile we never use polystyrene.

LPI
Perhaps the best known feature of a lenticular lens is its resolution which is measured in ‘lenticules’ per inch or LPI. The LPI of a lens can be very coarse or fine which is an indication of its intended viewing distance with high LPI lenses being more suitable for handheld viewing and coarse for distance viewing. Large format lenticular typically uses lenses in the 15 LPI (coarse) - 40 LPI (fine) range. LPI represents one of the first tradeoffs that must be considered when making a lenticular print, specifically because coarser lenses are often technically more capable - but the surface of the lens is more apparent. Coarser lenses hide neighboring images better to lessen “ghosting” between frames and offer greater viewing distances with more precision. Finer lenses excel because their surface structure can completely disappear when viewed from several feet, making them a good choice when there is a lot of fine detail, and smaller poster size pieces are often made on 40 LPI lens for this reason. But there are no hard and fast rules with LPI, large pieces are often very effectively printed on fine lenses - it all depends on how the artwork is set up and the expectations of the designer.

Thickness
For large format lenticular thickness is a range that goes from .033” to .15” and is typically affected by two factors, the LPI and whether the lens is meant for 3D or motion. 3D lenses are always thicker than motion lenses and lower LPI lenses are often thicker than higher LPI lenses. In many cases the thickness is not important to the end user, unless the prints must fit into an existing fixture that has certain tolerances. As a general rule large format lenticulars require a display support of some kind to prevent sagging, and fine art lenticulars are often mounted to a rigid substrate when framed or floated off a wall with cleats.

Viewing Angle
Lenticular sheets are engineered with a particular viewing angle with typical ranges from 25 to 47 degrees. Lenses with narrow viewing angles are usually meant for 3D and wider for motion, but both effects can be achieved with lenses of any viewing angle with varied results. The most apparent result of the viewing angle is how quickly the lenticular flips, with narrow viewing angles producing quick flipping imagery and a wider angle producing slower flips. The viewing angle also determines how many times the image sequence will repeat, for example a 3 image sequence will repeat 4 times using a 45 degree lens but 7 times using a 25 degree lens.

Viewing Distance
Lenticular lens has limits in terms of how effective it is at various distances. In general the same considerations given to LPI apply here, with fine LPI lenses having shorter viewing distances (1-10 ft) and coarser lenses being more suitable for distance viewing (5-30 ft). The effectiveness of a lenticular print beyond 30 ft is highly variable and the amount of movement required to engage the effect can become a deterrent to lenticulars with exceptionally long viewing distances.

Printing Processes
For large format lenticular there are multiple methods of production that can yield good results. Quality large format lenticular printing happens with expanded inksets (6+ colors), small picoliter drop sizes (7pl or smaller) and precision equipment. Previous generations of flatbed printers created lenticulars with a grainy appearance, acceptable for distance viewing or certain commercial applications but generally not for fine art. Methods using a two stage process where a print is made and then cold laminated to the lenticular plastic have been the gold standard for high quality fine art lenticular printing for some time but recent advances in flatbed printing technology have made the quality of direct to lens printing almost indistinguishable.