I have been working with matplotlib since 2013 (see for example issue # 1957) my system: Win10(64), IDE PyCharm, python 3.8.2 (64), numpy 1.19.2, matplotlib 3.2.2 and 3.3.0 I mainly use: matplotlib.pyplot as plt fig, ax=plt.subplot(...) ax.plot(...) ax.fill_between(......