kierongillen:

No, this is core craft questions. Very much the sort of thing you should be thinking about.

The quick answer is no more than 35 words in a panel, no more than 25 words in a balloon.

The full answer is based on old-skool wisdom. The original guideline is actually no more than 210 words *on a page*. Divide that by the number of panels to get your maximum, and that’s assuming all panels are equal size. The 35 words on a panel comes from a 7-panel page being a more common thing, when of course now American Superhero Comics tend to have lower panel counts. In practice, that is from an earlier era of comics – 210 words on a page would come across as incredibly verbose and overwritten to most people today.

I would advise sticking to the basic “35 a panel, 25 a balloon, MAXIMUM” for a while, but also bear in mind eventually you will want to break it for various reasons. 

Generally speaking, it’s also worth remembering you can edit after the words are on the page. If it looks like it’s too much, it’s worth trying to work out how on earth you can strim it.