Nevertheless, our experiments suggest that the defect engineering in graphene can be universally conducted in any ESEM provided the pressures, voltages, dwell times, shot pitch values, and doses can be carefully quantified and/or controlled. Our claim is also supported by the previously reported observation of a peak in the ID/IG ratio around 5000 µC/cm 2 by Iqbal et al., which is remarkably similar to our observations as shown in Fig. . µC/cm 2 in the case of CVD graphene, and from 1343 to 79000 µC/cm 2 for exfoliated graphene. In both cases, we see constant hole doping and tensile strain with increasing doses up to a threshold value (inflection point in the data), and increasing hole doping with constant strain at higher electron doses.