Full Idea
For Collingwood (and Croce) the work of art is an ideal object; …they are things that exist only in the mind, that is, only when one perceives. …The physical work exists to make this experience available.
Gist of Idea
Art exists ideally, purely as experiences in the mind of the perceiver
Source
report of R.G. Collingwood (The Principles of Art [1938]) by Gary Kemp - Croce and Collingwood 2
Book Reference
'Key Thinkers in Aesthetics', ed/tr. Giovannelli,Alessandro [Continuum 2012], p.103
A Reaction
This means that the paintings in a gallery cease to be works of art when the gallery is shut, which sounds odd. I suppose 'work of art' is ambiguous, between the experience (right) and the facilitator of the experience (wrong).