Rigid substrates: Cards, Metals and more

From cardboard to aluminium composite - there's a wide variety of different rigid media boards that are suitable for wide format use.

Last week we looked at various plastic sheets available as printing substrates and also for signmaking and displays, but the other types of rigid media suitable for sign and display use are just as versatile and varied. 

Most UV printers can print to most rigid materials, including wood and metal as well as stone and glass, though weight and handling characteristics may limit some of the more exotic substrates!

In addition, there are a number of substrates developed specifically for wide format printing. This includes paper-based boards that offer a good strength to weight ration, and which can be easily cut to other shapes.

Perhaps the most basic of these is corrugated board, which uses fluted paper in the middle between two facing sheets of linerboard.

There are different grades, determined by the mount of fluted material - the letter denotes the size of the flutes (the bumps inside the board) and therefore thickness and characteristics of the board.

Thus A and C Flute offer good structural strength while E Flute has excellent printing characteristics. B Flute offers a good compromise between strength and printability, while F flute is thinner but excellent for printing. Another common option is EB fluted board, which has a double layer of fluting, giving a good print surface together with a structurally sound board.

Heavy-duty alternatives

Dufaylite is a British company based in Cambridgeshire that makes honeycomb-based boards. The idea is remarkably simple, namely that paper arranged in a honeycomb structure can provide a relatively strong core that is both very lightweight and quite cheap. This structure is then sandwiched between a paper-based cover giving a flat surface suitable for printing on. Dufaylite uses recycled paper and water-based adhesives so that the products are very easy on the environment.

Dufaylite’s main offering for graphics use is Ultraboard. This is available with various surface finishes, including one with a Class 1 UK fire rating. Graphics can be printed directly or mounted via hot or cold laminators. It is suitable for interior applications such as retail displays and exhibition signage. There’s also an edging material available to hide the honeycomb interior from display.

Dufaylite has also developed a polypropylene version that uses the same honeycomb construction process. It’s a lightweight alternative to rigid and foam PVC boards.

Hexacomb, which is part of the Packaging Corporation of America group, manufactures Falcon board, a lightweight material made out of several layers of paper. The paper is slit and formed into a honeycomb which is then laminated, making for a very strong inner core. It can be cut or folded into different 3D shapes, and printed onto and is inherently recyclable. It’s suitable for long term interior point of purchase use.

There are three grades:

• Print, which is suitable for direct digital and screen printing:
• Build, which has a polyethylene liner for greater stability for creating 3d objects: and
• Mount, a lower grade board that is designed for mounting graphics to.

Simpler alternatives

Wood is also widely used as it’s inherently strong and looks good, though better quality wood tends to be more expensive.

A widely used alternative is MDF, or medium density fibreboard. This is made by mixing wood fibres with wax and a resin binder, which are then formed into panels under heat and pressure. The major advantage over natural wood is that there’s no grain or knots to contend with.

It’s also much cheaper than other types of wood and there are moisture resistant grades available. It’s flexible, yet very strong and dimensionally stable. It’s also easily routed or cut and shaped to form other objects. It’s typically available in 1220 x 2440mm sheets.

MDF has also proven popular for photo-printing. Most UV-curable printers can print direct to MDF, but for a better quality image it’s also possible to print to paper and then mount the print to the board.

Aluminium composites

Most UV and screen printers can also print direct to metal, though you may find that some metals need to be primed, and should certainly be cleaned with isopropyl or a suitable alternative.

There are a number of aluminium composite panels available that offer a metal finish, and are tough enough for long term outdoor use. Perhaps the best known of these is Dibond, as developed by 3A Composites. This uses a polyethylene core sandwiched between two 0.3mm aluminium covers, which is highly resistant to weathering and corrosion and suitable for long term outdoor use.

There are several variations in the range, including Dibond Digital, where the surface has been enhanced for direct printing with UV and solvent inks, and Dibond MIrror, which has a highly reflective finish similar to a glass mirror but considerably lighter.

The latest addition to the range is Dibond Structure, which has a textured coating that make it suitable for wall claddings and interior design.

Perspex Distribution also sells a number of aluminium composite products such as Alupanel (such as the examples below), which has a five year guarantee. This is a polyethylene core with aluminium skins, with one side having a satin finish and the other a gloss effect. There are various colours as well as metallic and mirror finishes. Another variation, Alufoam, uses a foamed polyethylene core that is said to be 30 percent lighter than the standard version.

There’s a budget alternative, Europanel, available in different colours and several lighter, cheaper versions.

It’s often said that the only limit to printing is your own imagination, and certainly today’s flatbed printers will work with a very wide range of substrates. However, depending on the inks in use, you may need a primer for some materials. Glass is particularly tricky because the smooth surface makes it difficult for the inks to key into, though some printer manufacturers, such as Jetrix, claim that their inks will work on glass.

Some vendors offer alternative ink sets for working with different materials. Most ink developers are aiming to extend the range of materials that their inks will adhere to, if only to take advantage of the growing market for industrial printing.