Operating Manual

16.4 Calculating roughness
With Ink Formulation it is possible in certain circumstances to use a
color assortment which was defined on a non-absorbent substrate (on
a substrate with a sealed surface such as Leneta cards, coated paper
or white, opaque plastic film), for formulations on absorbent substrates
(e.g. on uncoated papers).
The purpose of this option is so that a color assortment can be used not
only for one particular formulating condition, but as universally as possible,
i.e. also on substrates with different physical surface properties.
This can help reduce the considerable expense involved in creating
assortment colorant calibrations , because a separate assortment does
not have to be created for each substrate type.
Before this function can be used, it must be calculated for the absorbent
substrate to what extent the ink soaks into the substrate after printing. Ink
Formulation is able to use this function to calculate the extent to which
the printing ink has soaked into the substrate (absorption behavior). In
the program, this absorption behavior is described using the term „roughness“.
This necessitates creating a so-called „known recipe“ which is
mixed using colors in the assortment in question.
1. Create an ink mixture for which you know the exact proportions for how
much of each color it contains.
GretagMacbeth recommends creating a green for this purpose, consisting
for example of a mixture of green and transparent white, or a mixture
of blue, yellow and transparent white. When printed, this color should
not be too light or too dark, i.e. it should ideally have a brightness value
L* of approx. 50.
2. This ink mixture is printed on to the absorbent substrate (e.g. uncoated
paper). It is important that the printing conditions correspond to those
in practice (ink layer thickness, viscosity).
3. Define a new substrate (see Section 16.3 „Calculating roughness“).
4. Click on Measure to measure the ink in the substrate resulting from
printing the ink mixture.
16 • Processing and creating substrates 125