Colour management means measuring targets, defining tolerances and profiling presses to achieve the same results time after time. However, it is often considered to be fiendishly difficult to carry out, something that is undeserved. As Paul Chamberlain, Heidelberg UK’s colour management expert, says: “It’s not a black art, it’s just printing by numbers and as long as you have your standards in place then anyone could do it.”

Fortunately the ISO 12647 standard means that everyone in the supply chain, from ink manufacturers through to prepress software and press vendors, is working within known tolerances. It also defines best practice for printers, with a certification scheme to ensure that a company can both reach and maintain the required standard. But inevitably this involves consultants and ongoing testing that can be expensive. 

However, most printing companies should be able to achieve the ISO 12647 standard with a modest outlay on a spectrophotometer to measure the colour output and the appropriate software to make any necessary adjustments. 

Spectrophotometers

One of the biggest changes in recent years has been the introduction of a separate standard, ISO 13655, that defines particular measuring conditions. Thus M0 is for unfiltered tungsten light, while M1 covers D50 or daylight and UV light. M2 describes non-polarised light without UV and M3 is for light that is polarised with the UV filtered out. Of these, the main issue is M1, which deals with the effects of brightening agents in the media. Most spectrophotometers have been updated to reflect this.

There’s no question that the cheapest spectrophotometer is the X-Rite i1Pro2. It’s sold in different versions, though the main difference is the licence key that unlocks different features. The Publish edition allows for CMYK printer profiling as well as monitors and projectors.

However, X-Rite itself does not recommend this for the pressroom, saying that it’s really designed for pre-press use. Nonetheless, the i1Pro is widely used in pressrooms up and down the country and is generally regarded as being an extremely capable device, easily able to read the colour patches. 

X-Rite also sells a table, the i1iO, which can convert the i1 into an automated device capable of reading around 500 patches per minute.

X-Rite makes another handheld device, the eXact, which is designed for pressroom use. There are several variations but the eXact Advanced should be suitable for most pressrooms, albeit that it is nearly double the price of the i1Pro2. That said, the eXact is a robust device and can be used untethered, with a small display that tells you the results, whereas the i1Pro2 can also be used via its USB cable.

There’s an XP version of the eXact specifically for working with flexible films and targeted at packaging converters. Flexible films can be particularly challenging as the device has to be held such that it matches the film’s extrusion direction to ensure an accurate reading, but that’s not an issue with this new device.

X-Rite also makes an automated chart reader, the i1iSis 2, available in two sizes. The standard i1iSis 2 can read up to 1,500 patches on an A4 sheet in eight minutes, while the XL version can get through 2,500 patches on an A3 sheet in 10 minutes. They can also read barcodes to identify charts. They have built-in vision systems that are reasonably forgiving as to how charts are aligned as they are fed into the system, automatically correcting for misalignment.

X-Rite also makes a much more expensive Intellitrax spectrophotometer that’s designed specifically for pressroom environments. It’s an automated system that’s fairly quick to use, with X-Rite claiming that it can scan a typical press sheet in around 15 seconds. The latest version supports M1 measuring and can also handle thicker materials, up to 1mm, which will be easier for packaging converters. It has a new sensor that adjusts the scanning head so that it can now pick up colour bars down to just 2mm. It can show spectral and density measurements on-screen and can show recommendations regarding ink density differences between a target colour and a measured sample to help get the best colour match on-press. 

Most suppliers recommend Techkon’s SpectroDens as a direct alternative to the X-Rite eXact. As the name implies, it can be used as a densitometer as well as a spectrophotometer. It uses LED for D50 illumination and supports the M0, M1, M2 and M3 standard. It can measure a Fogra media wedge in 15 seconds. It’s designed to be used as a standalone handheld device and can connect to a PC through either a USB cable or Wi-Fi. 

For Drupa Techkon announced a new version of its SpectroDrive spectrophotometer that supports the M1 measurement standard. This is an automated system that uses a motorised scanner to travel across a colour bar printed on a sheet, and sends the data wirelessly. 

Konica Minolta has a long history of producing measuring devices for various industries including printing. At Drupa the company introduced an automated scanning spectrophotometer, the FD9 AutoScan. It takes A3+ sheets up to 330mm wide and up to 1500mm long. This can handle most standard patch charts including control wedges. It can work with M0, M1 and M2 data as well as reading QR codes. There’s an optional sheet feeder that can read in up to 100 sheets at a speed of 1,500 patches in four minutes, which is essentially one A4 sheet with up to 1,394 patches or half an A3 sheet with up to 2,928 patches. There’s a choice of USB and Ethernet connectivity and it can be networked between different devices. 

Konica Minolta also offers a couple of handheld spectrophotometers, including the FD7, which also includes densitometric measuring. It supports the M1 measuring mode and includes scan mode for fast measurement of test strips and profiling charts. It’s a handheld device but comes with a ruler to guide it along a row of colour patches. There’s also an FD5, with similar capabilities but only reports colorimetric data and lacks the scanning capability. 

The Italian company Barbieri has a number of spectrophotomers, including the SpectroPad. It’s a portable wireless device with a touchscreen for viewing the results. It offers D50 illumination to handle M1, M0 and M2 measurements. There’s also a new version, the DigiPress, designed specifically for working with digital presses. It can store colour libraries, including spot colours, so that operators can check printed colours for accuracy and for repeatability. 

Barbieri also sells the Spectro LFP, an automated table reader that can handle transmissive as well as reflective media up to 20mm thick and is widely used for large format printing. 

Another product the company offers is Spectro Swing, an automated chart reader that can handle up to 3,000 patches on media up to 1mm thick. There’s a choice between reflective and transmissive media, though the RT version can take both. As with all the Barbieri devices, it complies with ISO 13655.

Software

The other half of the equation is the software for making the profiles. It’s worth noting that not all programs will support all the available spectrophotometers though most will support the X-Rite i1 Pro and the Techkon SpectroDens.

Mark Anderton, managing director of Colour Engine, says that colour management requires good file preparation, calibration for the press and a verification system to check compliance with a standard such as ISO 12647, noting that Alwan’s Print Standardiser offers all of these. There’s a choice of editions, with the Start Edition able to work with a single handheld spectrophotometer, with CMYK plus one spot colour but able to ensure ISO 12647 and G7 calibration. Other editions allow for more devices and there are options for spot colours. It supports the ISO 13655 standard as well as multiple colour charts and wet and dry inks.

Bodoni Systems sells PressSign, which is available in several different levels. Essentially it’s a database solution so can handle multiple combinations of presses and substrates. Most editions can also allow for dry back, telling users how the colours will appear after they’ve fully dried out even if the sheet is measured immediately after coming off the press.

The most basic level is Print Buyer, which allows users to set a target and then meassure print quality in relation to that target. The next level up is the Standard version which can show you  how to make adjustment curves but only works with a short colour bar.

Consequently most companies opt for the Pro version. Ian Reid, managing director of Bodoni, explains: “It will show you what’s happening and how to make the adjustment across the press.”

There’s also a Global Print Management edition, which is for handling colour profiles across multiple sites.

Another popular option is Mellow Colour, which has developed PrintSpec ISO 12647 specifically for matching print to this standard. It’s designed to work with small press control strips and can generate a summary for each page about the inks, the overprinted colours, dot gain and grey balance. It can keep a track of targets and tolerances and it’s also possible to set up your own standards.

Inevitably there is more to achieving good colour management than simply buying the measuring tools and software. Chamberlain concludes that standardisation is the key to colour management, adding “not just on the press but also stocks and pre-press”. He explains: “Once you’re happy with your consumables and have standardised them you must stick with them because any that are out of line could cause problems. So standardisation is the key fundamental.” Most press vendors, including Heidelberg, offer various courses to teach press and pre-press operators how to achieve optimum colour management.

Finally, there’s little point relying on a spectrophotometer to measure your colours if that device is itself out of calibration. Most vendors recommend returning these devices at least once every 12-18 months, depending on how critical colour management is to the business.