Assets you create or edit in Canvas are accessible directly through the Canvas where they were made. Users who have visibility to your Canvas can see the items but cannot edit or save the output. They are not automatically added to a board but you can save them to a board manually at any time.
In your Canvas, select the item(s) you want to save
In the toolbar that appears, click Save
Choose to Save to board and pick where in your workspace your new asset(s) should live
OR
Choose to download to your local drive
Items saved to your workspace from Canvas will be accessible to your workspace and associated board users. These items show the upload source as Canvas in advanced metadata so you can easily filter for these files through Air's powerful search.