How do I go about becoming ISO compliant, is it difficult?

I can outline the process here but feel free to email or call me for more details on the subject and what relates more specifically to your needs.

ISO compliance of course relates to a variety of standards depending on the process you use and wish to be compliant with. Coated and Uncoated paper obviously are based on different standards for example and when relating to press compliance, things such as screening, conventional AM or FM (Stochastic) also need to be considered. ISO compliance also relates to proofing and is not always concerned only with compliance on press but in a press house naturally the two go hand in hand.

The thing to realise first is that there is no such thing as generic ISO densities. Densities are calculated for each press/ink/media combination individually. Any densities supplied by industry suppliers etc are only a starting point and may well be very close to what you are already using. The custom densities are calculated measuring 100% solid patches when dry with the aim being to match the particular ISO standard Lab values.

Lab is both density and colour and as it is a dry standard these values have to be correlated with the whatever the wet densities were that produced the required dry Lab values. While strictly speaking, secondary RGB colours (overprints) are considered only as informative for ISO compliance, I am a firm believer that serious consideration needs to be given to this important area, after-all, all process colour print work is about overprints, nobody orders a solid CMYK job.

Once the correct solids have been established and only after they have been established accurately, the tints can be measured and new dotgain curves created. One of the great misconceptions in the print industry is that many people make the assumption that regardless of the print densities in play, the dotgain curves perform a colour correction roll. If the dotgain percentages are correct then the gray balance will be correct. This is definitely not the case.

Dotgain curve values are a prescribed percentage at each tint, 25%,50%75% etc. For example for the Sheetfed Coated standard, Paper Type 1 has a dotgain of 14.3% at 50%. In other words if you are used to dealing in Dot Area, the DA is 64.3% at 50%. The important thing to consider here is 50% of what? It is not enough to say 50% of 100%. What is 100%? If for example the Magenta 100% was lower than required to provide the correct dry Lab values then the corresponding 50% would naturally be lower as well. Bye bye gray balance. Gamut size too.

The ink hues must be correct as well otherwise you will never match the standard within the allowable Delta E tolerances regardless of whatever density is used. Ink suppliers can all now supply ink that is capable of matching the required ISO standard but it doesn’t necessarily mean this will immediately transfer to a match on press. Ink contamination is a major reason why dE tolerances can be exceeded when trying to establish the solid density values. Ideally compliance work is carried out with fresh ink in the tanks and clean rollers.

Another area to keep in mind during press compliance work is the issue of uniformity. It doesn’t do the production work much good if compliance can only be achieved in a specific spot on the page. I supply uniformity reports along with the other reports during my compliance work. Uniformity issues can account for problems matching the proof even after the compliance has been supposedly carried out and passed.
Where possible I also like to check the plates for accuracy. There are advantages to running a linearisation curve in the plate rip in addition to a calibration or press curve.
Also don’t forget about the often overlooked vital area of lighting for accurate assessment. You must have areas of the correct viewing conditions to be fully ISO compliant. If it doesn’t look right then all the numbers in the world saying all is good doesn’t make it so.

To get the ball rolling, when having been approached about performing compliance on press work, I start by supplying a file or control strip which can be run on a normal job. I can then assess this once printed and determine before the ISO print runs if the inks are of the correct hue and if compliance is possible when optimal densities have been established. Dotgain is checked to see that not only is each channel itself in tolerance but also that the CMY spread is in spec.

In late 2016 new print standards were released. These were to enable greater accuracy using brightened papers that are so much more common these days than when the previous standards were established. While much has been printed and said about the new standards, especially relating to optical brighteners, there are real world benefits that go far beyond this and I think these real benefits of the new standards have been rather poorly promoted and without wishing to sound disrespectful, I don’t think they are anywhere near fully understood.

All the publicity I have heard has been squarely aimed at the points of optical brighteners and M factors. This comes across as blinding clients with science rather than highlighting the reasons aside from such things that result in better prints on press and a better match between press sheet and proof along with the fact that you can now get genuine ISO compliance on uncoated media instead of a workaround that merely got you as close as was previously possible . i can assist you with complying with these new standards or even determine if you should change or stay with the older versions.

In answer to the original question, is it difficult? Like anything, if you don’t know how then yes it is difficult but with the proper assistance there is absolutely no reason why anyone should not be able to achieve ISO compliance and reap the ongoing benefits.