12. A computer-implemented method, comprising: receiving ink content applied to a document via input from a pen to an input surface while in a transient ink mode, the transient ink mode effective to cause ink applied to the document to be applied to a transient ink layer separate from the document such that the ink does not becoming part of primary content of the document; detecting that the pen is removed from proximity to the input surface; initiating a timer responsive to said detecting; removing the ink content from being displayed on the document and propagating the ink content to the transient ink layer for the document responsive to expiry of the timer; and displaying a visual representation of a user, the visual representation being selectable to retrieve the transient ink layer and cause the ink content from the transient ink layer to be displayed along with the primary content.
12. A computer-implemented method, comprising: receiving ink content applied to a document via input from a pen to an input surface while in a transient ink mode, the transient ink mode effective to cause ink applied to the document to be applied to a transient ink layer separate from the document such that the ink does not becoming part of primary content of the document; detecting that the pen is removed from proximity to the input surface; initiating a timer responsive to said detecting; removing the ink content from being displayed on the document and propagating the ink content to the transient ink layer for the document responsive to expiry of the timer; and displaying a visual representation of a user, the visual representation being selectable to retrieve the transient ink layer and cause the ink content from the transient ink layer to be displayed along with the primary content. 15. A computer-implemented method as recited in claim 12 , further comprising: causing a visual affordance of the transient ink layer to be displayed; and enabling the transient ink layer to be accessible via interaction with the visual affordance.