27 March 2017 Digital Printing Technologies

The printing is on the wall

The trends in interior decor favour the use of digital printing, but the question is whether the digital transformation is led by existing suppliers or by a new breed of digital only businesses.

It is a logical progression. Inkjet, from printing photos to printing posters, can now print entire walls. The arguments that have driven digital printing from its outset – lack of inventory, single item production, no makeready costs, production on demand – can equally apply to wall covering production.

This alone would be reason enough for printers and developers to look hungrily at the wallpaper sector. The amount of ink needed to cover a single wall will make suppliers positively salivate.

But it will be some time before major retailers replace the rolls of wallpaper in their out of town stores with a rollfed printer to create wallpaper on demand for walk in customers. Homebase did offer a bespoke print service of this nature, but it has been discontinued, presumably for lack of demand.

For the moment wallpaper printing using standard inkjet printers is confined to producing photographic murals for feature walls – a child’s bedroom with a cartoon character for example – or for commercial premises.

Conventional wallpaper production, using block printing, gravure or screen printing, continues to hold sway, in the same way that litho continues for many commercial print applications.

The equipment is amortised, it results in low cost high volume products, wallpaper manufacturers are tied in to an established distribution chain, and other functions like embossing for example can be delivered inline. Digital based around roll to roll inkjet printers cannot achieve this.

This is not preventing equipment manufacturers from pitching the idea of digital wallpaper production. A number of online print providers have appeared to service a direct to consumer market, in the main for mural style products, while others are stretching into bespoke wallpaper printing as partners alongside interior designers and architects. And one or two major wallpaper producers are starting to look at the potential in producing high value wall coverings digitally. It is a familiar pattern.

HP was one of the first to push the idea of digital wallpaper printing. Its Latex technology has an inherent advantage over other inkjet technologies. The water based ink does not have the lingering smell that afflicts solvent inks, nor the problems associated with UV inks which mean that these are ruled out for wallpaper production.

However, HP is no longer alone. Eco-solvent machines from the likes of Epson as well as latex machines from Ricoh and Mimaki are there to rival HP in rollfed inkjet.

However, inkjet is not the only game in town: Xeikon has installed its 3500 to print wallpaper and has a package of hardware and applications around the offering. For higher volumes, KBA has discussed the potential of its Rotajet inkjet web press for wallpaper printing. IIJ has designed an inkjet unit suitable for wallpaper printing as a replacement for technologies currently used.

John Corrall, IIJ managing director, discussed the approach at the InPrint 2016 event in Milan. He sees the market as very similar to that for ceramic tiles which switched from a predominantly analogue process to inkjet in just a few years, driven by the reduction in the cost.

The European demand for wallpapers is in gentle decline, prompting manufacturers to seek innovation. Digital can provide more colours, more designs, shorter runs, all familiar advantages of digital from books to packaging. But these companies are still industrial scale producers and need a volume machine to replace ageing machinery.

Digital print can overcome the colour match problems that beset conventional manufacture and force consumers to compare batch numbers when choosing to decorate a room. “I think the current offerings are too slow or too narrow,” he says. “Also there are a lot of regulatory requirements for wallpaper and we have doubts that some of the digital wallpaper today meets these requirements.”

Wallpaper destined for a child’s bedroom, for example, may need to be laminated, just in case the child ends up eating the substrate or even licking a hand that has rubbed across the surface. The dangers of heavy metals and other poisons in the ink have been known ever since arsenic in the ink of the wallpaper of Napoleon’s bedroom in St Helena was blamed for the death of the former emperor.

The materials used are no less important. Corrall reckons there to be 40 or more common wallpaper stocks in use. Then there are the specialist materials developed for inkjet printing. They clearly need to be matched to the technology used in terms of presenting the best image, but must also be resilient to stretching in order to guarantee that the join between one roll and the next will be perfect from top to bottom. Not all materials achieve this.

The Digimura materials, supplied through Papergraphics, are mentioned again and again by printers in the sector. They suit commercial applications where there may be frequent changes in decoration, for a bar or restaurant for example, as some will enable the top layer to be quickly peeled away and a new outer layer added rapidly.

There are other choices. Innotech has created a range of wallcovering materials which cover the spread of applications. “The first consideration is how long the graphic needs to stay on the wall, and whether it might need changing frequently which will help you decide whether to go for a fabric or a magnetic material,” says Innotech marketing manager Kieran Dallow.
“Second, what surface is it being applied to, and what existing graphics are on the wall?  Where a graphic is being applied over an existing graphic, or any bright colours, it’s generally best to go for a grey back material to block out these colours to maximise the vibrancy of the new graphic when it’s on the wall.”

The company has materials that fall into these categories from Vertex Texture, a polyester material designed for wallpaper applications to printable magnetic materials that allow the material to be stripped from the wall and a new design applied. Soyang will also supply interesting materials that are far from conventional ready pasted.

HP knows this. Terence Ragunath, business development manager for the Printed Interiors Decoration division, says that barriers remain for the widespread dissemination of digital wallpapers. The technology is eminently suitable. The output meets the ISO, Greenguard and other standards which are recognised indicators of safety.

HP’s interests started six years ago with research into the potential as part of a look at the next set of applications for inkjet printing. It identified the wall covering manufacturers around the world (Corrall reckons there are 300 or so machines dedicated to wallpaper production in use) and Ragunath says HP approached them.

“Some have bought into the digital story, some have not. It is currently a very analogue industry: the route to market is different, the workflow is different and beyond the manufacturers there are myriad others that are involved in design, specification and sales,” he says.

The production technology used favours blocks of colour, generally six to eight inline with a maximum of 12 at a time. The circumference and width of the cylinders sets the finished product and the repeats used, generally 900x900mm. This is a restriction for designers and where perhaps the greatest opportunity for digital printing lies.

Digital can break free from the convention of repeated patterns, particularly for feature walls. Instead of a pattern of pink roses, digital can create a wall where just one giant rose dominates. “There is stuff that people want that you can only do with digital printing,” he says.

This plays into the design trends that are rapidly spread across the world thanks to designers using Instagram or Pinterest, to make over television programmes and websites like Houzz.com. These have also contributed to the decline in wallpaper usage. Thirty or more years ago, every wall in a semi-detached house would be covered with a wallpaper. Then came painted decoration with terracotta coloured feature walls.

Now the design oyster has been opened, led by photomurals of forest scenes, walls or children’s cartoon characters. These are the easiest for digital printers to offer, says Ragunath, and the easiest for consumers to buy via a website.

Canon’s European director of strategy and business development Dirk Brouns is also cautious about the speed that the market will develop. It will be about the murals, about decorating hotels and commercial premises before householders rush to cover the interior of their flats and houses with digital print.

“We envisage the market for digital wall coverings and wallpapers growing substantially in the future, but perhaps not as fast as people are predicting. At the moment digital makes up only a fraction of the overall market,” he says.

The new UV gel technology that Canon has announced this month would be ideal he reckons: “It’s non toxic, durable, colourfast, producing high quality prints for almost any flexible media application. And it breaks through the speed barrier,” says Brouns.

Welsh business WallpaperInk started with a Roland DG aiming to print wallpapers and sell them across the world. It has expanded to include a variety of different inkjet machines and has a range of design styles for customers to select from. “We run machines from three different manufacturers,” says Scott Evans, who started the wallpaper arm in 2012.

These are imposed on the target wall with space allowed for any doors or windows and the order placed. The company will supply the finished roll wrapped in climate resilient material, with a wallpaper seam roller, a break off knife, measuring tape and video to show how to apply the wallpaper. The appropriate paste is also supplied.

The company does not want to spend too much time answering customer queries. “We are trying to make buying the wallpaper as simple as possible. There are three materials we print on and will laminate these for use in children’s bedrooms,” he says.

A crucial skill is understanding how to enable the Pontypridd business to be discovered by customers in Australia. Evans has a background in digital marketing. “The SEO is quite complex,” he says.

Wallpaperink’s customers are guided through galleries of different images, they select from three material types and pay. It does not offer more complex design functionality, say for rooms where more than wall will be covered, or where doors or windows exist. It is possible to accommodate this through online design software, but such applications are not as intuitive as they should be, says Ragunath.

He likens these tools to the early word processing software before wysiwyg computing. “3D design is not easy for the end user to get to grips with. They need to understand Photoshop or other tools to manage colour,” he says.

The software needs to cope with doors and windows as well as different angles that stairs can make, where ceiling meets wall and so on. Online is going to be restricted to flat surfaces for at least the immediate future.

However, the complexity of room designs tends to lend itself to the sort of project management that printers can provide, from understanding the room space, using Photoshop to apply a design and then calculating the best way to print the correct amount of material.

The print provider can also deploy colour management expertise to replicate what the customer has conceived, as nobody is going to thank you when the colour of the wallpaper does not match the colour of furnishings or piece of art.

The print business also needs to understand that bright ‘in your face’ print that is perfect for advertising posters is far from ideal for a wallpaper that householders are going to have to live with for years.

While latex printing is ideal for the market, eco solvent inks are also used for wallpapers. Paul Restarick of Epson Europe explains that the latest SureColor S series machines are particularly suited to wallpaper printing.

It can offer nine-colour printing, uses eco solvent inks that are durable, safe and have a wide colour gamut. “The GS3 ink is durable and fade resistant, its colour gamut is amazing, especially in red areas. This is fantastic for corporate colours where orange is extensively used. And they meet Greenguard requirements.”

Printing edge to edge is essential for wallpaper printing, and the ability to slit the printed reel into the widths that decorators are used to dealing with. For patterned wallpapers, tiling software can manage the repeats that are needed or vary these according to a designer’s wishes. The sharpness of Epson’s print output makes the machine highly suitable for mural printing compared to those with a softer result.

On the SC-S machines, Restarick points out that the take up reels are controlled under tension to prevent stretch across the printed paper. Any stretch across the width will make it difficult to achieve the matching that is necessary when joining the drops together.

This is a function also of the paper used. Some papers are apt to stretch, something that may not be noticed until the material is applied to the wall when a seamless joint at the top of the roll may be far from a match at the bottom.

“We have had a lot of success in this market,” he explains. “But wallpapers produced in this way are still quite niche, still quite expensive.”

But designer wallpapers can be eye wateringly expensive even without digital printing, reaching several hundred pounds a roll for some designs and substrates. The search is always for a design that others do not have, the exclusivity that makes a house a home, or propels a boutique hotel into a highly desirable location.

The cost is a barrier for Canon’s Brouns also. So too the way to break into the market. It has specialists in the wallpapers market that it can put in front of customers he says. The technology is up to the task, delivering the dimensional stability and with the ink types that are necessary. “There is also the question of print width. A digital printer that cannot print a ‘standard’ wallpaper roll width is never going to be a big seller,” he says.

Inkjet does not have an exclusive hold on the market. Xeikon has created a wallpaper decoration suite for its presses, where the 3500 single-sided machine in particular is positioned for wallpaper printing. A dedicated take up reel is part of the offering in order to slit the web and ensure that the tension of a printed roll is correct. A pre humidifier is used for non-woven substrates. Its QA-I toner is safe and 1200dpi print resolution covers the bases in terms of quality. Output speed of 600m2/hr is faster than rollfed inkjet, if not the speed of a gravure machine.

Xeikon has participated in Heimtextil, the major European exhibition for home decoration that takes place in January each year. This show sets the tone for the rest of the year in terms of designs that will be applied to walls, fabrics and rooms in the next year, the equivalent to Paris fashion week.

This year tropical themes were everywhere, some green in Pantone’s colour of the year. Digital production can respond to these trends far faster than conventional production chains can adapt.

This is a key reason why digital printing has great potential for wallpapers. Xeikon has customers in conventional wallpaper production. This is the same market that Corrall wants to reach with IIJ’s concept press. The tipping point is close he reckons.

While digital printing will be more expensive due to the cost of inks, the elimination of expensive prepress, storage waste, and supply chains unable to respond fast enough to design trends, means that as with the ceramics market, wallpapers may be poised to become the next market to flip from analogue to digital production.