By Digital Output Staff
A lot of talk related to floor graphics involves the material and the print side isn’t addressed as frequently. Every application from wallcoverings to banners and vehicle wraps have their printing nuances. Ink set choice, drying/outgassing of a print, ink laydown, and ink durability are variables to consider for floor graphics.
All in all, “there is generally nothing unusual about printing floor graphics versus other types of graphics. Most media are compatible with industry inks and most are easily printed,” admits Tom Wittenberg, large format industry relations and events manager, North America, HP Inc.
However, the width of the printer in question is a consideration. Lily Hunter, senior product manager of ecommerce, Roland DGA Corporation, says on average, floor graphics range from smaller options of about 12×12 inches to medium-sized graphics around 36×36 inches, all the way to those applications that cover an entire floor. In this case, “it’s important to consider quality at speed for short-run batches of multiple smaller graphics, as well as stability over distance for those larger print applications.”
The printer isn’t the only piece of hardware where size matters. “When printing floor graphics, especially graphics meant for long-term use, you need to be thinking of lamination. Specifically ensuring the size of your media matches the length of your lamination and laminator. Generally, the size ranges from 54 to 63 inches,” recommends Lewis Jones, applications specialist, Mimaki USA, Inc.
So while this article focuses on printing to substrates intended for floor graphic application, Hunter stresses that “in the case of floor graphics, success is due to the right combination of advanced ink sets, high-quality print media, and the choice of laminate for the application.”
Above: HP Latex inks don’t need to outgas and allows the PSP to go right to finishing.
Ink Set Choice
Latex, eco-solvent, and UV ink are popular for printing floor graphic material on wide format devices. In terms of durability, longevity, flexibility, and color gamut the various ink sets each offer advantages. Married to the ink set is the time it takes for it to dry or outgas prior to—if required—lamination.
Wittenberg says “most ink sets do the job nicely for floor graphics. However, the key is what you plan to offer in the way of turn times. Most industry inks require drying/offgassing prior to any lamination. HP Latex inks can skip this step and go right to finishing, saving many hours of lost productivity.”
Mark Rugen, director of education, Mutoh America, Inc., argues that eco-solvent inks are the go-to for floor graphics. “The primary reason is because these inks actually penetrate the vinyl substrate and that makes them very permanent. Eco-solvent inks are great for temporary graphics printed on removable vinyl that are intended for just days and not weeks.”
“Solvent inks have a larger color gamut, so if you’re looking for photorealistic images or more vibrant colors I would lean more towards them. There are flexible UV inks and you don’t normally need to worry about extreme curves with floor graphics. However, if you require bending a 90 degree angle like stairs, I would gravitate towards the flexibility of solvent inks,” suggests Jones.
Outgassing does need to occur with solvent-based inks. “If a laminate is applied before the completion of outgassing, the gas can put pressure on the laminate and this can result in de-lamination or separation of the laminate from the media. We recommend a 24 hour period of outgassing before laminating, but if a graphic is to be applied for less than a week, less time, perhaps only a few hours might be fine,” shares Rugen.
UV ink and its subsequent iterations can also be used for floor graphics. “With UV inks you don’t need to wait for an outgassing time before laminating. For speedy production that is the ideal choice,” says Jones.
“If you want print and go—print in one time and cut and apply—Canon UVgel is the most durable without any added protection. Part of the ink durability is its resistance to abrasion and also cleaning agents as well. The Canon Colorado has a large color gamut and one-step textured floor products are top applications on that printer,” recommends Angel Georgiou, specialist, marketing senior, imaging supplies, Canon Solutions America.
Floor graphic media is available in many base options including aluminum foil or vinyl and film. The way it handles ink laydown is an important consideration, with the number one factor involved being the thickness of the material.
Testing any new material before running the full job is recommended to avoid errors. “Normally the thicker the material the more chance you may run into problems with printing on roll-to-roll machines. You may need to adjust the printhead’s height, or slow the printer down by increasing the passes so more ink is being put down. It helps to ensure there is a tension bar pulling the finished print when working with difficult media,” advises Jones.
“Ink laydown is not an issue with the variety of media used for floor graphics. Where it does get challenging to an extent would be in cutting, where more down force is needed with the result being that one would go through blades more quickly than other media,” notes Wittenberg.
Many floor graphic materials are included in a two-part system, meaning they require lamination. In this case, some of the durability requirements of an ink set are negated.
Rugen believes ink durability is always important, no matter the media or application, but since floor graphics are usually laminated, the durability of the ink isn’t considered a focal point.
“The lamination pretty much does negate the durability concern. However, one issue that does occur is with UV inks. UV inks go down in varying thickness whereas HP Latex ink is fairly uniform in its laydown. Putting a laminate on UV is like putting it on a series of small peaks and valleys versus a smooth plain. The result is that the former affects the adhesion of laminate and ultimately the durability of the overall product,” says Wittenberg.
Conversely, Jones says ink durability is important in regards to the application of the floor graphic. “When applying a finished print and laminated design to a floor, you might need the image to pull and bend. If you’re working with a media that requires heat to apply the graphic there will be a degree of stretching of the media. The inks should be durable enough to withstand this stretching and still adhere to the media. If they are not, sections of white cracks where the vinyl and ink separate will be visible.”
Many printers are equipped with the capability to run white ink or even additional colors, special varnishes, or glosses beyond traditional CMYK. Applications like packaging, wallcoverings, or even vehicle wraps leverage these unique consumables to standout. While floor graphics find favor with them, they aren’t as commonly seen as used with this application.
“Generally, specialty inks offer incredible opportunity to create unique signage, displays, and customized objects. Floor graphics tend to benefit from a straightforward approach, especially when part of the goal is to create a safe interaction between the sign and any person in contact with it,” explains Hunter.
That being said, Wittenberg suggests white ink be used on clear floor graphic media, to make an image pop out from the intended surface versus fade or blend into the floor color. “Beyond this, we don’t see a critical need for white inks. In terms of other special colors, that will all depend upon the customer’s design request,” he continues.
Specialty media is where white ink shines. “UV white ink is essential when printing on non-traditional vinyl like neon, foil, or transparent media. You can use the white ink to make sure sections of your printed graphic don’t get washed out by the media insuring your finished design doesn’t have a translucent effect,” adds Jones.
Georgiou believes there isn’t much use for white ink on floor graphics because vinyl features a white base, meaning there won’t be enough contrast between the ink and media. “However, if a print provider is printing on clear material—textured vinyl for example—you might use white to produce three-dimensional images or more dimensional floor graphics.”
Minimal Challenges, but Awareness is Key
Floor graphics present numerous challenges in terms of choosing the correct material for the job, however the right printer and by extension ink set are also imperative to the final outcome. While there are no overwhelming challenges associated with printing to material that will eventually be adhered to a floor, there are considerations to keep in mind like how long it will take for the ink to outgas before applying lamination, what level of ink durability is needed, and if specialty colors like white are necessary.
Jan2022, Digital Output