Notions of authenticity underpinning conservation practice have been challenged by artistic and museum practices that contest the mere possibility of singular material existence of objects. These practices work within the liminal, in-between, space some objects currently occupy. But how can conservation conciliate the preservation of an object's material manifestation, with the ethical need to recognise its other material possibilities? The ethical implications of conserving objects whose existence is contested are discussed. Drawing on feminist theory, it is argued that the path towards a fairer, inclusive, and sustainable conservation practice is dependent on the recognition of difference. The ethical ramifications that emerge from practices of conservation that reflect on performative inbetweenness, here called liminality, are explored. By demonstrating that the act of observation is always contingent, the ways we understand and conserve objects materially change them. How those changes can exclude their material possibilities and their becomings, are discussed. A possible ethical approach to conservation is proposed, that goes beyond modernist views of the object being conserved, recognising the exclusions inherent to any process of conservation, celebrating the diversity of material existences of objects we ought to protect.