The purpose of this study is to reach a better understanding of the complex fading behavior of ink jet prints and to demonstrate the difficulties in providing reliable tests. Test conditions chosen for this research were: high-intensity fluorescent light (framed and unframed samples), airflow, and ozone and nitrogen dioxide to better predict the influence of possible environmental pollutants. Two ink sets, a dye-based and a pigmented one, printed on two different media (a photo glossy and a matte paper), were tested. The samples were read with a spectrophotometer to get an overview of the fading behavior over the whole spectrum. An additional advantage of this approach is to not be limited to the filters used in densitometers, because they are not ideal for the inks used for ink jet printing today. The fading behavior of the various ink concentrations of the samples were monitored and described over time. These data lead to a more detailed description of the fading process than normally published data showing only an endpoint for one specific ink concentration. It is crucial to describe the fading processes as accurately and completely as possible during the time of development of ink jet materials. Advantages and disadvantages of various methods for describing the fading behaviors will be discussed.