A new version of the ISO 12647-2 standard is on its way and is expected to be published early next year.
The first revision of the standard since 2013 clears up some long standing issues around printing conditions, calibration, substrates, tolerances and characterisation data. There has been a long road to reach agreement on how the litho printing standard should be updated. In this case it was agreed that revisions to the existing standard were needed in 2019, German standards agency Fogra was engaged to help with the work. It says: “Due to the difficulty of reaching compromises among all participating countries, the process extended over eight years. After a long process, the relevant ISO committee, TC130 WG3, has finally reached an agreement.”
The new version is now to be published before the end of the year as a ‘draft international standard’, While this is still subject to a vote at the start of the new year, its provisions are almost certain to be accepted. ISO 12647-2: 2027 will then become the official ISO standard for offset printing.
There are now three printing conditions to consider: native, registered and relative. With the native conditions the most frequently used substrate types are defined with target values. For coated and uncoated, the existing Fogra51 and Fogra52 conditions remain with an average 1.5% increase in midtone values for black.
When the white value of the substrate differs from that in the native or registered printing condition, the target values need to be adjusted in what the standard calls a relative condition and conversion formulae are provided. These are likely to be included in measuring devices and colour software.
There are additional methods for achieving a calibrated state. Instead of being based on density measurements of solid patches, a colorimetric method may also be used. The impact is a more eye-friendly way of calculating colour gradients for example, but there is limited practical experience of this in the real world, so Fogra advises caution.
It is cautious too about the reliance on a neutral grey which is at the heart of the US G7 colour system.
It notes that different print can result from the different calibration method and a print may be compliant with the standard under one method of calibration, but not another. Which is used needs to be specified in advance.
A universal characterisation data has been developed for offset printing on coated papers. This delivers consistent print results regardless of the calibration method chosen and is published as Fogra62. The European Colour Initiative has taken this data and created an ICC profile as a first step towards an internationally recognised profile PC1, which would further simplify consistent colour printing by avoiding the need for different variants of a profile to cover the same printing conditions.
