Dr. Henk G. Merkus has been working at Delft University of Technology for about 35 years, the last 20 years of it in Particle Characterization in the Particle Technology Group. Since over 15 years he has been a member of ISO/TC24 on Sieving and Other Methods for Particle Size Measurement. Although retired, he continues to be active in giving courses on this subject, in the Netherlands as well as in Sweden and the United Kingdom. Dr. Merkus is the editor and author of two other Springer books: "Particulate Products" (2014) and “Particle Size Measurements” (2009). Dr. Gabriel M.H. Meesters is affiliated to DSM Food Specialities and Delft University of Technology Delft. He has 10 patents filed and 5 issued to his name.