Each zipped folder corresponds to a letter (with the nomenclature of the French National Archives). There are folders for each scan performed. The information about the location of the analysis in the letter (page and line), the dwell time per pixel (in ms) and the beam size (in micron) are in the folder name. In this folder, there is a file corresponding to the data cube of the elementary maps (in raw format that can be opened by ENVI software or Python software for example), a file explaining the organization of the data (in rpl format), one or two images showing the area analyzed in the letter (in tif format). For the data cube, the z axis is composed of 4096 bands (XRF spectra are recorded between -0.956700 and 39.989201 keV with a step of 0.01 keV). The "preliminary tests" files correspond to the first analyses carried out on one word to optimize the parameters. There may also be folders corresponding to the point analyses including the spectra (in spx and txt format) made on the paper, the writing ink (WI), the redaction ink (RI) or the superposition of the two (ET or T) and an image of the analysis location.