Why a custom printer profile?
The precise numbers that need to be sent to a printer to produce any particular colour depend on at least three things:
Every time a digital image is sent to a printer a print profile is involved. The print profile acts as a 'translator' that ensures colour values represented in the digital file are translated precisely into the right combinations and amounts of the inks you are using in your printer to reproduce the colours faithfully on your chosen paper.
Every printer manufacturer supplies generic profiles for their printers and original inks. High-end photo printers come with a set of more specific profiles tailored to the printer maker's branded papers and inks. Additionally, some makers of high-quality third-party photo print papers often supply profiles on-line to match their papers with popular photo printers.
Snapshot photographers usually find these profiles 'good enough'.
So why would you need a custom-built profile?
Photographers who produce fine-art prints for competition and display usually want:
Below are some of the reasons why these characteristics can not be guaranteed for so-called 'generic' profiles:
The way a printer makes colours on printer paper is dependent on at least these three variables:
To make a profile it is necessary to make prints of standard colours and measure them. There's more detail on this process on the next page.
To make their generic profile, an OEM (original equipment maker such as Epson, Canon, HP) presumably makes test prints using a representative sample of a particular model of printer and a representative sample of a particular paper. For obvious reasons an OEM will use their own ink sets. In developing a profile for a particular printer-paper combination it is likely that the OEM will average the measurements from the samples to minimise any impacts of equipment or paper manufacturing variability.
The process followed by third party paper manufacturers such as Ilford or Hahnemühle will be similar. Profiles are only ever supplied for a few particular printer models assumed to be using the OEM's inks.
However manufacturing variability almost certainly guarantees that no individual printer and the particular batch of paper will require precisely the profile created from averaging sample measurements. How much this could be an issue depends on how colour critical the photographer's work is.
There is a completely different situation when a photographer, for whatever reason, wishes to use a third party photo paper for which the manufacturer has not created a profile. Photographers sometimes guess that, because "the paper looks and feels just like such-and-such from the OEM", the printer will behave as it does with the OEM paper. Occasionally, the person is lucky and the printed colours are pleasant – even realistic – if not precise. More often the prints are strikingly off in some or all colours.
An even more problematic situation arises when a photographer wishes to use third-party inks. Neither printer nor paper manufacturer could, or would, make available print profiles for inksets other than those of the OEM. Leaving aside the impossibility (and understandable lack of incentive) for a manufacturer to be able to locate and test all possible ink copies, there remains the issue of the accuracy with which a third party ink maker has been able to analyse the composition of the original inks to copy them.
In short, it is very unlikely that any print profile supplied by a printer or paper OEM will work well with an unknown paper. From the photographer's point of view this becomes a colour crap-shoot.
The Good News
The good news is that you can have a printer profile custom made that is optimized for the printer on your desk, with the inks and papers that you use, to help you get the most out of your printer. How?