The quality of coated products depends strongly on the structure of the coating layer. Confocal laser-scanning microscopy (CLSM) and X-ray micro-computed tomography (mu-CT) are used as non-destructive techniques for the quantification of coating microstructures, especially coating layer thicknesses. Combined with image processing, it is possible to evaluate and correlate chord lengths and coating thicknesses. In this study two different kinds of core particles were coated with crystalline and film-forming coating materials by fluidized bed spray granulation. The thicknesses of the coating layers were investigated using both measuring methods. Motivated by observed differences in the obtained CLSM results for the layer thickness, a new evaluation procedure is developed and discussed. (C) 2015 Elsevier B.V. All rights reserved.