Wolfgang Haug on the use of the word 'immaterial':
"In this sense, one might characterise the practice of the ‘immaterialists’, who have fashioned an essential element of their symbolic capital out of the talk of ‘immaterial labour’, as itself ‘immaterial’. The ‘intellectualisation’ of growing segments of social labour that is driven forward by the development of the high-tech mode of production, as well as the breaks and lines of conﬂ icts on this ﬁ eld, are more likely being covered up by the imposition of the decisionist category of ‘immaterial labour’ on them."
Page 184 the article: Haug, Wolfgang Fritz. 2009. “Historical-Critical Dictionary of Marxism Immaterial Labour.” Translated by Joseph Fracchia. Historical Materialism 17 (4): 177–85. doi:10.1163/146544609X12562798328251.