Portucel and Whatman CF11 fibres treated with CBD-FITC. The fibres treated with a concentration of 60 μg/mL (or 2 mgCBD/gfibres). The images were acquired with an exposure time of 600 ms. The white squares identify the areas selected for analysis. The more fluorescent parts (black regions on the analyzed images) are out of range (calibration shown elsewhere), and were therefore excluded from the analysis.