Merging documents with shared layers

To add a canvas from one Omnigraffle document to a different document, you simply drag that canvas from the first document and drop it into the canvas list of the second document.

But some care is needed when shared layers are involved, especially when transferring canvases from differing versions of the same document. You also need to be careful if you are in the habit of using standard shared-layer names in your documents. (E.g, "Background" or "Grid.")

Omnigraffle resolves shared layers in merged files based solely on the names of the shared layers. The destination document's shared layers always win out when confronted with same-named shared layers from another document.

Say you have two documents, A and B, and you are dragging a canvas from A to B.

If the canvas dragged from A has a shared layer whose name does not match that of any shared layer in B, that shared layer will be added to B and remain associated with the canvas.

However, if the canvas dragged from A has a shared-layer name that exists in B, the shared layer from A will not end up in B; instead, the same-named shared layer in B will be assigned to the dropped canvas, replacing the shared layer from A.

So if you want any shared layers to be retained in a canvas dragged from A to B, make sure that B has no conflicting shared-layer names. You can always rename the conflicting shared layer in one document or the other before dragging to avoid the problem.