In Chapter 1, Getting Started with OmniGraffle you learned that the canvas is the place where all your diagramming work is done. You make shapes, you edit shapes, and you delete shapes. You even connect shapes to each other using connectors.
Generally you will use only one canvas: You make a single diagram for your report, export it to a JPEG or a PNG file, and then you are done.
However, what if you need to include more than one diagram in your report, presentation, or e-mail? You may end up in creating one diagram per file. There is nothing wrong in having one diagram per file—it may even make a lot of sense. However a more sensible approach may be to have all the diagrams in one OmniGraffle file.
If you have ever created a big diagram, your diagram may inadvertently have spread over two physical pages. A logical step would thus be to use one physical page for each diagram that you need. There's nothing wrong with this but it may become a hassle and you may lose control if you have...
