Thirty commercial proteins were prepared at 1.5 pmol/µL in three different subsets of 10 proteins each. Proteins from these subsets were spiked to a 15-µg Escherichia coli background in different amounts and five different mixtures were prepared in triplicates. The final amount of each protein in each mixture was either 100, 200 or 400 fmol/µg of E. coli background for the subsets marked as 1, 2 and 4, respectively. The generated dataset with known concentrations of spiked-in proteins was used to evaluate the performance of several processing tools of MS proteomics datasets.