1. Sustainable inks - boldly going where no man has gone before?
There has been much talk in recent years of sustainable, or "green" inks.
In fact, 'talk' is probably the right word for it - greenwashing abounds - from printers
that consume enough power to light the average football stadium to the quaint
notion that mixing in some UV curable ink with solvent ink will somehow, magically,
produce a "green" solution (well, it does if you mix cyan with yellow - but that's
another story!).
The term "greenwashing" was coined by the New York environmentalist Jay
Westervelt in 1986 and he applied it to situations whereby more money or time is
spent on advertising the "green-ness" of a product than is spent on actually adopting
environmentally sound practices. An example of this is the cynical use of cosy nature
scenes (waterfalls, forests etc.) as images on the packaging of harmful substances.
In general, the arch enemy in an ink is its VOC (volatile organic compound) content.
VOCs are chemicals with a high vapour pressure resulting from a low boiling point,
causing a large number of molecules to evaporate from the ink and entering the
atmosphere.
Anthropogenic (i.e. the effect of human activity on biophysical environments - a
term first used by Pavlov) VOCs are regulated by law as they are known to have
short-term (acute) and long-term (chronic) health effects. Research into these
effects is made difficult by the fact that studies need to be long-term, and the
volumes of VOCs involved are so small.
Side effects of VOC's include such nasties as; eye nose and throat irritation, nausea,
vomiting as acute symptoms and cancer, liver/kidney/nervous systemdamage as
chronic symptoms.
Confusion over labelling of chemicals from country to country has led to the UN
intervening, resulting in the Global Harmonized System of Classification and
Labelling of Chemicals (known as GHS or CLP) coming into effect in December 2010.
This has been implemented by most countries in Europe and the Americas, and
some key countries in Asia. This should eventually raise the awareness of harmful
substances.
The shift to digital printing across the board means that any innovations are likely to
come from this methodology - Benny Landa said at IPEX 1993 "Anything that can
become digital will become digital. Printing is no exception."
Most aqueous (water-based) inks are sustainable, with dye ink, in particular,
containing, essentially, plant dyes which are similar in nature to food colourings.
Generally, the limitation in their use is seen to be their poor light-fastness and water
resistance. Recently, though, we have seen a resurgence in the use of such inks in

2. single-pass head technologies like the Memjet printhead which offers affordable
high-speed digital printing with a remarkably stable dye ink in terms of light and
water resistance. This single -pass technique is also being seen in the new
technologies being used in the transactional print sector with machines from Screen,
IBM/Ricoh, Océ, HP et al - so we can expect these huge investments in R&D to have
spin-off benefits in the wide format signage printing sector.
Of course, most of us still consider that the only practical solutions for digital
outdoor prints are solvent and UV-curable inks. Whilst there has been a shift away
from 'hard' solvents to eco-solvents (the term originally meaning 'economy') to
alleviate the effects of VOCs, this has done little to address the global situation.
New water-based technologies like HP's latex ink, and Sepiax's resin ink etc. are
starting to have an effect on new media like tissue paper, styrofoam, aluminium foil
and many more for new 'niche' applications. For basic outdoor banner printing,
however, the marriage of PVC banner/solvent ink (both emitting VOCs) is still
unbeatable in terms of cost per square metre. Until endusers start to insist upon
sustainable prints and force economies of scale, then this will stay the case.
Many enduser consumers talk-the-talk, but when they find that the cost is a few
pennies more per metre for a green solution, they will fall back on old (cheaper)
methods.
We are seeing legislation in environmentally-conscious countries, along with the
green-motivation of leading supermarkets and other large retailers, plus edicts from
cosmetic companies requiring their print providers to switch away from harmful inks
and media (ironic - as the perfume industry is laden with VOCs!). This is starting to
turn the tide and forcing the industry to change.
It should be remembered that the move to green (i.e. non-harmful) inks provides the
signmaker with new business areas like hospitals, schools, nurseries, food processing
and the like. New methods of digital printing are being introduced all the time in
areas such as labelling and packaging, which are allowing the industry to apply digital
print in hitherto inaccessible places.
It has been said that the "Holy Grail" of digital printing is an odourless ink which
prints on any surface, at high speeds, with; high resolution, wide color gamut, low
energy usage, abrasion resistance, water resistance, etc.
We are making major strides every year towards this goal.
Will we reach this goal at some time in the future? - I don't know - but it is
interesting to note that you never see any posters on the walls inside the Starship
Enterprise!