The description of the problem generator can be found in:
2DCPackGen: A problem generator for two-dimensional rectangular cutting and packing problems Elsa Silva, José F. Oliveira, Gerhard WäscherEuropean Journal of Operational Research, 237, pp. 846-856 (2014)DOI: 10.1016/j.ejor.2014.02.059and the files donwloaded here: