Q: What should be done when the figure is large and there is no space below to write both the caption and the footnote?

It’s great that you are paying such attention to detail and to the journal’s guidelines. You no doubt want your paper to be perfect in every way at the time of submission – something that’s likely to be appreciated by the journal. :-)

Coming to your query, no, it won’t be wrong to place the caption and footnote on the next page, but it will certainly look odd. It will look something like what’s called orphan text in page formatting. But I guess your figure is indeed so big that if you push it to the next page (to make the figure, caption, and footnote all appear together), then the previous page will look a bit vacant.

In these cases, the best solution or workaround is to try and move the figure one para below (or up, as the case may be), without of course compromising too much on the flow. If that doesn’t work, you can keep this minor niggle aside for now (in case you’re in the middle of the paper) and come back to it once you’ve completed the paper. Hopefully, when you’re revisiting the formatting toward the end, you’ll have a better idea of how to make it work.

And if you’ve tried everything and still don’t have the perfect solution, you can go ahead and submit to the journal. You may mention this in the cover letter. The journal is unlikely to penalize you over a relatively small matter. Hopefully, during the revision, you may be able to visualize a better way to present the figure.

Also, note that this may not be an issue for an online-only journal, but only for a print version. For a possibly similar example of presenting large figures in manuscripts, you may view this video (the last part): A step-by-step guide to formatting tables and figures in your manuscript

For more information on how to present figures and footnotes in your manuscript, you may go through the following articles:

• Tips on effective use of tables and figures in research papers
• Footnotes in tables (part 2): formatting, spacing, and punctuation

Finally, if you’d like to utilize our artwork preparation service, you may learn more here: Artwork Preparation

Hope that helps! All the best for the formatting and submission!