No. A caption doesn't have to be on the drawing canvas... and neither do
graphics. But, you asked:
It appears that whenever I add a caption to a drawing canvas in Word 2007,
it inserts the caption in a text box. Can this be changed?
And that's the question I answered.
The real question, I would guess, is how to make a graphic and a caption
stay together. I can think of at least five ways:
1. Include the caption as part of the the actual graphic (in which case,
automated caption numbering cannot be used).
2. Put both the caption and the graphic onto the drawing canvas.
3. Put the graphic in line with text, and the caption immediately below
it.**
4. Put the graphic into a table cell, and place the caption into a cell
immediately below it (borders can be turned off so the fact that it's a
table isn't obvious).**
5. Use any floating wrapping style for the graphic, put the caption into a
text box, and group the graphic & text box so that they stay together.
**My personal preference is for #3 or #4, depending on how I'm planning to
use the document.