I've previously posted about balloons, but here I want to extend that to captions and thought bubbles. I'll begin by recapping my thinking on the balloons.
My initial pages for the story, in an attempt to create a period effect, used balloons that looked like scrolls and banners. Initially I tried to use a different style of 'balloon' for each character. It looks quite nice on some pages, but at other times, like this draft of page 9, it got a bit busy, due to the combination of different characters speaking, and thought bubbles.
Changing the text to the Alex Toth (tribute) hand-lettering font makes it look a bit better (note, I improved the spacing after I did this page).
I think my decision to change the balloon style to the borderless style shown below, was a good one. I think that the borderless balloons manage to be readable, without encroaching on the drawings. There is no point trying ti update the balloons on the above example, as it only reads against a coloured backgrounds shown below.
I have occasional captions, which require to be clearly distinguished from the dialogue balloons. The first one i attempted was on page 14, as shown above. I drew a scroll shape just in white, with no border, which seems to work pretty well.
There are also a couple of instances of Uccello's thoughts that need to be either captions, or thought bubbles. A few lone rectangular boxes might look incongruous, and scrolls might cause confusion with the narration captions, e.g. '...and yet later...' as seen above. Perhaps the best solution is actually obvious and simple - have them like the speech balloons, which, (lets face it), are more like bubbles anyway, but instead of tails, use the traditional small bubbles to indicate whose thoughts it is. That seems sensible, but I won't know for sure until I try in on a real example.
In the page below I had a thinks balloon/caption required in the bottom right panel. I tried a few options, of which this was the least worst. I think it's hard in this panel, as the thought bubble is a response to the word balloon, so needs to be read after it. not sure I've solved this, but will keep trying.