You can define complex inks by specifying the percentages of their component inks. You may
find this useful when it comes to job costing as all the user has to do is specify the 'complex'
name and the components will be split out automatically for costing and re-ordering as required.
This may be of special interest to screen printers, where ink is a more major part of a job's cost.
A complex ink is made up of different simple inks in varying proportions. The percentages of the
various component simple inks should of course add up to 100.
