The growing world of digital textile printing

There are tremendous opportunities in digitaltextile printing, and even as new types of applications are opened up bydigital technologies, there is little doubt that many traditional textileapplications will shift to digital. Richard Romano makes this assertion as he talks numbers, marketsand trends.

Thereare few print applications these days that are not moving towards some kind ofdigital production. Digital technologies have been used in textile printing formany years, but it is only recently that they have gone beyond simpleprototyping and sample generation. However, not all textiles are the same-andnot all digital textile printing is the same. There are different printingtechnologies suitable for different types of textiles and different textileapplications.

One ofthe biggest stumbling blocks in the printing of textiles, much less the digitalprinting of textiles has been ink and substrate compatibility, which, afterall, is the perennial challenge in any print market segment. Getting inks toadhere to fabrics and then be able to survive whatever end-use is intended forthe printed materials has been a substantial challenge. However, developmentslike ultraviolet (UV) curing and latex inks have solved many of thesechallenges, and it could be said that it is largely the new inksets that havemade digital textile printing possible.

The textile printing market

Talking about the "textile printing market" is a bit like talking about the "commercial printing market". It consists of a very wide variety of products and niches, each of which has its own dynamics. Direct mail printing is very different from magazine printing, which is very different from business card or letterhead printing, and so on. Likewise, the textile printing niches can be very different from one another. Banners and signage are very different from apparel, for example.

We can identify three basic categories of textile printing.

A) Garment and Apparel

This category includes, essentially, anything that can be worn. It can

include, but may not be limited to:

*t-shirts

*caps and headwear

*sportswear

*bags

*jackets

*towels

*aprons

*children's/infants' wear

*uniforms

*bandanas

*blankets

*patches

*sleepwear

*pennants

*rain gear

*swimwear

*silk scarves/ties

Research conducted by the Specialty Graphics Industry Association (SGIA) in the US has found that t- shirts, athletic apparel, caps and headwear, and performance apparel are the top product categories among garment printers, with the strongest growth area being performance apparel. (The numbers in the figures in this section are from 2013, the most recent year for which we have data. SGIA has discontinued this particular study, but is working on a revamped version. These data also refer to US print service providers, but should provide a good idea of the product mix).

B) Signage/Visual Communication

This is where we can classify what is known as "soft signage", although this category can include many other types of products, as well. We can define "soft signage" as "large-scale display graphics printed on a textile based substrate." This category can also include, but is by no means limited to:

*banners

*posters

*point-of-sale/point-of-purchase (POP/POS) displays

*indoor wall graphics

*trade-show displays

*advertising specialty

*flags

*parasols

*block outs

*outdoor advertising

*beach flags

*backdrops

Currently, many of these product areas (like POP/POS displays, posters, and other types of displays) are printed on rigid or mountable materials. Those that are printed on soft substrates (like flags) are still often printed using an analog process. The top product areas for companies in this category, according to SGIA, are banners, indoor wall graphics and window displays, with indoor wall graphics seeing the strongest growth.

C) Decor

Barely discussed at all as recently as five years ago, digital decor is a fast growing new market. While wallpaper and posters have been printed for decades, if not centuries, items like curtains, drapes, furniture coverings, tables, chairs-you name it-can now be digitally printed in some fashion. Not all of these products will be printed on some kind of textile material, but for some aspects of decor-curtains, for example-it is difficult to imagine a "hard" substrate. Wall coverings are a top growth area in this category; indeed, the entire category of digital decor is one that is seeing strong growth.

A caution about commoditisation

When it comes to perceiving opportunities in the top growth markets, there is a danger that they can become over-served by print providers to the point of becoming commoditised. Take the product category of banners. There is a sense that banners have become commoditised, and thus there is little differentiation from one banner printer to the next, a situation that results in businesses competing solely on price which thus becomes a "race to the bottom".

There is very little margin in products that have become commoditised (small-format work like business cards are a good example of commoditisation in action). This is not to say that it is a completely dead product area-actually, commoditisation usually means that there is a substantial and healthy market for a product-but it is a very saturated one. Better opportunities may be found further down the list.

All of the above markets and products should give some idea of the vastness of the digital textile printing market. Not all of them can be produced using the same printing technology; so, let us look at the various methods that exist for printing on different kinds of textiles.

Digital textile printing technologies

There are many different types of textiles and fabrics, and no one inkset or printing technology is suitable for all of them-although printer and ink manufacturers are trying their darnedest.

Direct-to-garment printers: These are inkjet printers-not dye-sublimation- that print directly on t-shirts, hoodies, tote bags, hats, and other such items, and are not typically used for raw fabrics or materials that will later be sewn into garments. Directto- garment printers are used for short-run printing, not high-volume industrial production. These printers are only compatible with cotton (or maybe up to 50 per cent blends) substrates.

Latex printers: "Latex" is a generic chemical term that refers to a "stable dispersion (emulsion) of polymer microparticles in an aqueous medium" and is not related to the natural latex exuded by plants or the synthetic latex used to make gloves or other rubber-like items. So, these inks are perfectly safe for those with latex allergies. Latex inks are water-based and are suitable for a wide variety of coated and uncoated materials in addition to textiles. Since latex inks are water-based, it is claimed that they are more environment friendly than other inksets. However, the inks cure under extreme heat, which from an energy consumption standpoint may offset any environmental benefit from the inks themselves.

Ultraviolet (UV) printers: The UV flatbed that a shop may be using for rigid materials can also be used to print fabrics, although it is not the ideal platform for textiles. UV inks are more expensive than other inks, and cure as a thin polymer film which makes fabrics stiffer and perhaps uncomfortable to wear.

Dye-sublimation and related ink technologies: While all of the previous printer/ink technologies can be used for textile printing, the real action is happening in dye-sublimation and related dye-based printing, some of which are often confused with dyesublimation.

Dye-sublimation: There are two primary varieties of dye-sublimation printing. In transfer printing, the printer images on a special paper that has a coating designed to hold and then later release (under heat and pressure) the printed image. After printing, the paper is brought into contact with the fabric in a heat press, and the ink embedded in the paper is converted to a gas and penetrates directly into the fibres of the substrate. For chemical reasons, polyester fabrics are required for transfer dyesub printing.

An up-and-coming variant of dyesublimation printing is direct-to-fabric printing (not to be confused with direct-to-garment mentioned earlier), which eliminates the need for transfer paper, although it still needs to be run through a heat press to fix the dye on the fabric. This type of dye-sublimation requires pretreated fabrics (again, polyesters) that give the ink something to "grab" on to, and historically pretreated fabrics were expensive and of poor quality. As dye-sublimation has taken off, the fabrics are getting less expensive and the quality is getting better and more consistent.

The dye-sublimation inks used in direct-to-fabric printing penetrate further into the fabric than those used in transfer printing. The result can be less vibrant colours and softer text and images, as well as more showthrough on the reverse side of the fabric. As a result, the top application for direct-to-fabric right now is flags.

A lot of development is going into direct-to-fabric dye-sublimation and new inksets and machines will whittle away many of its limitations. This is one of those areas where the landscape will likely look very different in six months.

In addition to dye-sublimation, there are other dye-based textile printing inks, which are differentiated by the kinds of fabrics on which they can print.

Reactive dye inks: Also known as "fibre-reactive dye inks", these inks are best-suited to natural cellulose fibres like cotton since, as the name implies, the dyes become physically part of the fibres.

Acid dye inks: Acid dye inks react with the fibres in natural or synthetic polyamides like silk, wool, and nylon.

Pigment inks: Here is where a lot of the action in industrial textile printing is happening. Generally, pigment inks can print on virtually any fabric, and cure via heat or UV radiation. One problem with pigment inks is that they require a bonding agent. Another is that, for a given quantity of ink, the more colour (aka pigment) it contains, the less bonding agent, and thus the less washfast the print is. On the other hand, the more bonding agent, the more washfast, but the less vibrant or colorful.

Durst water technology: Durst Imaging has recently introduced what it calls Durst Water Technology, an aqueous (water-based) ink for directto- fabric textile printing. Conceived as an alternative to UV, solvent, or even dye-sublimation, the new water technology is said to be odourless and more environment friendly than other ink technologies. This last point has become increasingly important, especially in Europe, where initiatives such as REACH are placing hazardous and potentially hazardous chemicals under increased scrutiny. Interestingly, it is European environmental concerns and regulations that are driving a lot of interest in soft signage, as bans on polyvinyl chloride (PVC) and other rigid plastic substrates have sent print buyers and providers looking for substitutes, namely textiles. 

Going green

There is much pressure in virtually all corners of the printing industry to pay closer attention to environmental issues. As mentioned earlier, one of the drivers of the shift to soft signage has been to reduce or eliminate the use of PVC and other plastics. The irony, however, is that the fabrics used in much digital textile printing are polyester-based. While there are natural polyesters and even synthetic polyesters that biodegrade, the majority of the synthetic polyesters used in textile printing do not. Therefore, disposal becomes an issue, and recycling of used and discarded soft signage and other printed materials needs to be practiced with diligence.

Another area of concern is that some varieties of digital textile printing (those using reactive dyes, for example) require post-printing washing-sometimes two or more cycles-to remove unfixed ink and prevent staining and other discolouration. Some also require steaming-not just exposure to heat and pressure-to fix the ink. Excessive water usage has become an environmental concern, and as digital textile printing grows, water consumption will consequently rise. As a result, there is a desire to shift to print technologies that do not require a steaming and/or a washing step, such as using pigment inks. Think of this as a "work in progress".

Onward

There are tremendous opportunities in digital textile printing, and even as new types of applications are opened up by digital technologies, there is little doubt that many traditional textile applications will shift to digital, as well. The challenge will be for companies to ensure that digital printing methods meet the quality expectations-in terms of colour, resolution, and other such attributes-that customer have come to expect from analog textile printing. Companies looking to get into this space should be sure to do their homework before making the leap.