Assuming you would like to create a Kindle comic, the best way to format your comic is through Kindle Comic Creator. Kindle Comic Creator is a free tool that allows authors and publishers to turn their comics, graphic novels, and manga into Kindle books. With Kindle Comic Creator, you can upload your images, create panel layouts, and preview how your book will look on Kindle devices. If you're satisfied with the results, you can then export your book as a Kindle Format 8 (KF8) file, which can be uploaded to the Kindle Store.