Antibodies directed against Histone post-translational modifications are essential research reagents in chromatin biology. However, they suffer from variable properties and insufficient documentation of quality. In this comment in F1000 Research, we request that antibody manufacturers and vendors should provide detailed lot-specific documentation of quality, rendering further quality checks by end-customers unnecessary. Moreover the application of polyclonal antibodies is intrinsically unsustainable, because experiments cannot be reproduced after the corresponding batch of an antibody is sold out. As a consequence of this, rigorously speaking, large data sets in chromatin biology exist in a “grey” area outside of applicability natural science rules, since it is impossible to repeat the underlying experiments. We note that a shift from polyclonal antibodies towards sustainable reagents like monoclonal or recombinant antibodies or histone binding domains will be necessary to improve the long-term reproducibility of experimental work in this field.