An often underrated part of photography chain. For a printed image to be viewed properly, it must be shown under controlled lighting conditions. If you look at a picture of the common incandescent light, the colors are quite different than if you look at it under fluorescent light. What is the right proofing illumination?
There is an ISO standard that may be helpful. It says the following to betraktningsljuset should be 2000 lux and a color temperature of 5000K. This corresponds to normal daylight around sunrise / sunset. It is also important to CRI's light source, ie spektralfördeningen to be as close as possible naturligtdagljus. It sets the right high standards and today's LED lamps are rarely good.
Of course, the room does not have colors or daylight features that affect the entire. Betraktningsljuset going to be more than twice as strong as normal office lighting.
Cheap and good betraktningsljus you can get by using Solux halide. They have a high CRI index of around 98 by max 100. That means they have a light very similar to the daylight as spectral be standardized on.
Important to remember, of course, in what light you will view your images. Do you know that images always appear in an incandescent light of a certain spectral images should of course be prescribed for these conditions. Do you show your images under varying and unknown conditions, it is wise to stick to the standard.
The quality and attitude of printers and print programs are important. Black and white prints are often color cast, and are different under different lighting.
Read This document from X-rite that produces professional calibration equipment.