Paper Chase - Permajet's FB Distinction - part 2 of 1 2 3 4

by Mike McNamee Published 01/10/2011

We first inspected the colour gamut and the table shows that the paper is fully exploiting the HDR ink set, with a gamut volume in excess of 1 million Lab3 units.

We are unsure as to why we squeezed some additional gamut but the increase was gratefully received! We also achieved greater accuracy using our bespoke profile when compared with the more generic PermaJet profile. This is usually the case; it is very rare indeed that a generic profile outperforms a bespoke one. The data are tabled and are better than average for this type of test. Even the HiGAM values are better than our average for the full colour sets.

The balance of errors was even across the lightness, chroma and hue channels. Generally the lightness errors were due to the colour being too dark (but only by between 1% and 2%). The error spread across the hue range favoured the blues (closer to the base tone), the yellows being the highest errors. The HiGAM errors were actually more evenly spread with the weighted average hue error being just 0.58; here again the higher component was in the lightness, at an average of 2.3% too dark.

Overall then a very satisfying set of colour statistics.

Barytas are much loved by the monochrome fraternity. This is hardly surprising as the smell and surface finish on many inkjet barytas are intended to mimic that of air-dried, fibre based silver-gelatine media. We measured Dmaxes of 2.39 using the generic profile and 2.17 using our bespoke profile (all-colour printing).

The metamerism colour Inconstancy Index (CII) measured at 1.93ΔE00 and 1.80ΔE00 respectively (D65-Tungsten A on 50% grey). These values we would rate as good, the CII isactually lower than we have been measuring with HDR ink on other types of media.

Differentiation was up to 252 RGB points and down to 30 RGB points with the generic profile and 20 RGB points with the bespoke profile (which probably explains the higher Dmax, the file was simply darker all over!). Overall the bespoke profile was slightly worse on density errors, the results were 1.3% too dark.

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1st Published 01/10/2011
last update 06/11/2019 11:07:38

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