According to duplicate Bug #378760 "Printing pages with objects with opacity != 1.0 gives bad results", it can be mitigated by using fill-opacity and stroke-opacity instead of opacity (then only the transparent object's region is converted to bitmap).
According to duplicate Bug #378760 "Printing pages with objects with opacity != 1.0 gives bad results", it can be mitigated by using fill-opacity and stroke-opacity instead of opacity (then only the transparent object's region is converted to bitmap).