This tool set is designed to rapidly measure white paper characteristics: Whiteness, Tint, Brightness, Fluorescence, and Opacity. The fluorescence is the difference in the brightness measured without and with a UV-blocking filter. This filter can be real, in the form of a thin plastic sheet, or simulated, if you have an i1Pro 2 that supports the M0 (Ill-A) and M2 (UV-cut) Measurement Conditions as defined in ISO 13655-2009 (a description of the M0/M1/M2 measurement conditions can also be found in the FluoCheck tools screenshot page). In the above screenshot the Fluorescence is 9,5 (= 97,5 - 87,9 where each number is rounded for display purposes). The opacity is obtained by ratio of the paper luminance (the Y of XYZ) measured on the black backing on the luminance measured on the white backing. The paper used for the above measurements displays a strong fluorescence typical of "Bright White" papers sold for office reports, and which is acceptable for such a use; however, this is not the best paper for high-quality photographic printing if you are looking for a time-stable print that can be viewed in different illumination settings containing various amounts of UV light (i.e. halogen lights indoor vs daylight). Whiteness tools requirements (not provided): For fluorescence measurements: o An i1Pro or i1Pro 2 which is not UV-Cut. o You must use either a thin, transparent, UV filter, or an i1Pro 2 which supports the M0 and M2 measurement conditions. For the other measurements: o Compliant white and black backings. Please note that you can use the Whiteness tools to easily check white and black backings compliance and characterize any UV filter you may have. You will find filter suggestions and a filter characterization procedure in the CT&A Help manual; click on the link below for an Application Note dedicated to fluorescence measurements (this app note does not include the capabilities of the i1Pro 2 but remains useful for all instruments): AN-8 How to optimize the accuracy of fluorescence measurements with BabelColor CT&A The screenshot below shows the saved image obtained with a 2X print scale; the image can also be generated at a 1X scale.