The more digital print dominates, the greater the demand for versatility. It's not that long ago when we were only able to use ink-jet processes on roll-fed materials but, as advances continue to push their way into production processes, we've all become aware of the demand to being able to output direct onto more varieties of material.

But there's a world of difference between thicker and thinner, apart from the obvious caliper or grammage. Taking the ability to print direct to chunkier substrates is down to more than its thickness; overall weight can play a part and this, in turn, means that a printing machine is going to have to be tough enough to shoulder the extra burden of the media's extra depth. The current average is around the 5cm mark, presumably deemed to be a sensible limit as it covers the majority of rigid options which are used in the display market. In these families lie solids and corrugateds, conventional looking boards and composite structures which can be cut, creased, folded and recycled.

So the restrictions in working with thicker materials lie in the design and configuration of the printing machine, and the distance which is achievable, not only for the print-heads to be at the right height to jet properly but for an optimal curing distance. If we are to see an increase in industrial and specialised applications which call for a greater depth, doubtless machine developers will factor this in to new equipment and the way that chunky boards can be handled efficiently.

Conversely, working with thinner materials brings about problems of their own. First, print engines need to be able to handle sheets and rolls without any creasing and buckling during the process. Fine media has other idiosyncrasies, depending on structure, with greater attention needed to be given to ink performance and saturation.

Probably the most critical consideration with thinner media is during the drying process. Where heat is used, a fine grammage is likely to be more susceptible to damage. Likewise, the methodology used in UV-curing can be addressed either by LED lamps or by using cold mirror dichroic reflector technology to lower the temperature by diverting the heat generated by infrared energy away from the material.

Certainly, with greater versatility being expected from today's digital technologies, there is more than a passing interest in being able to work with material thicknesses which fall outside the normal range of every day use. Thus, modifications to machines will need to be made to make many of these more practical in regular applications.