Did some more digging regarding this message: Unknown value for media-col: (unknown IPP value tag 0x34) Choices: [u'media-bottom-margin', u'media-left-margin', u'media-right-margin', u'media-size', u'media-source', u'media-top-margin', u'media-type'] Selecting from choices: media-bottom-margin And found that this is a new type of message named IPP_TAG_BEGIN_COLLECTION which seems to be some some list in a list attribute. pycups has no idea what to do with this attribute. jocke