ZBrushCentral

Document size changes when I re-open file

So I save my project as a a ZPR , but when I re-open it the document size changes (Document width and Height in Document menu) and there’s a white border marking what seems like the original document size.

Anyone know what’s happening here?

Thanks

.zbr is the filetype for documents and the white line is a indicator of where you can click in rotate\move around when the screen is filled with mesh.

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