How to Format a Webcomic. The wonderful thing about a webcomic--aside from the low-to-no start-up costs involved and the freedom to produce just the kind of comic you want--is the fact that you can make your comic any shape, size or combination thereof that you can dream up and set up your website to contain! Called the "infinite canvas" by Scott McCloud, it definitely has its high points: you can add animations, sound or create a unique user interface customized to your content. At the same time though, you have to keep in mind your audience, how they will be viewing your comic and how far you want to push the boundaries between online comic and something else. Now that we've established this much, here are some suggestions for formatting your web comic.
Choose between vertical or horizontal for your primary orientation. Whether you choose a newspaper-style strip layout with three, four or five panels per strip, a magazine-style page format with fixed or varying panel layouts or a single-panel that updates with each click, consistency will help both your readers know what to expect and give you a certain framework to work within.
Maintain consistent gutters between the panels regardless of their orientation. Gutters provide a brief break or pause in which action or reaction can take place, the reader can digest what was said or done in the previous panel and can ready themselves for what will come next. Perhaps gutters are even more important in digital comics than print, as the strain of reading images backlit, as on a computer screen, can cause misinterpretations and blurring of details.
Avoid making your readers scroll by making your comic, in whatever form each update takes, fit within a standard computer screen. Granted, standard is a bit of a misnomer, as resolution can vary from computer to computer, but there are some that are more common than others. 1280 pixels seems to be the most common screen width with heights ranging from 800 to 1024 pixels (according to my own analytics data). If scrolling is completely unavoidable, scrolling down is a lot easier than across for most people.
Determine what format will best fit the story you are trying to tell. Practical matters aside, trying to fit a sweeping epic of a story in a standard 4-panel format is unlikely to work, so serve the story just as much as the technology it's presented in.
Prepare your files with an eye towards maximum versatility. This usually means having high- and low-resolution copies on your hard drive (and a separate backup drive or disc), but with the numerous ways people have of accessing the Internet these days, it also includes being able to reformat your strip for reading on a mobile phone or keeping your text legible when zoomed-in, while still keeping file sizes at a minimum.
Consider print limitations if you plan to produce hard-copy collections. This includes options like color versus black and white, since color is always more expensive to print, as well as common page sizes for print collections, since custom sizes can come with custom prices.
Design your website so that the comic is the primary focus of the page. While your logo, the page navigation and your contact information should also be high on the list of priorities, make sure that none of them detract from the comic itself.
Don't be afraid to borrow ideas from other webcomic artists; seeing how others do it and what clicks with you will lead in the right direction for your own strip.