Two decisions that shape everything else
Before you draw a single panel in a vertical comic, you have to decide two things: how wide the canvas will be and roughly how long the episode will run. Both seem technical, but they affect how the story feels. A canvas that is too narrow forces you to shrink details. An episode that is too long can tire readers, and one that is too short can feel thin.
One caution applies throughout. Specific requirements differ between publishing services and change over time, so this article gives general principles rather than exact numbers. Always check the current upload instructions of wherever you plan to publish.
Why width matters
Most readers will see your comic on a phone, held upright, with the image scaled to fit the screen width. This means the width you draw at is mostly about quality, not about how big things look. A wider canvas gives you more pixels to work with, so lines stay crisp when the image is scaled down. A very small canvas may look soft or blurry on a high-resolution screen.
At the same time, drawing at an enormous size has costs. Files get heavy, software slows down, and detail you add may never be visible at phone size. A reasonable approach is to draw at a width that your chosen platform recommends and that your computer handles comfortably.
It also helps to think about what readers actually see. Because the image is scaled to fit the screen, a panel that looks roomy on a large monitor may feel small on a phone. Text that seemed fine while drawing may turn out to be tiny. Checking your work at phone size is one of the most useful habits you can build, and it connects to the broader subject of phone readability.
Length: how much is too much?
Episode length is measured in different ways: the total height of the image, the number of panels, or how long it takes to read. For readers, the practical measure is time and effort. An episode that takes a few minutes to read is common in the format, but there is no single correct length.
Some points to consider:
- Shorter episodes are quicker to produce and easier to publish on a tight schedule. They can work well for comedy, gag strips and quiet slice-of-life stories where each installment is a small moment.
- Longer episodes give room for complex scenes, action or emotional buildup. They take more effort to make and can strain a creator working to a weekly deadline.
- Consistency matters. Readers form expectations, and if length varies wildly from one episode to the next, the experience can feel uneven.
The right length also depends on the story. A scene that needs space should get it, and one that is finished should end. Padding an episode with filler panels to hit a target usually shows. So does cramming too much in and rushing.
This links to the question of schedule. A creator who can produce a certain amount of finished work each week can set a length around that, as discussed in the material on a sustainable production schedule. Choosing a length you can maintain is often wiser than choosing an impressive one you cannot.
Slicing a tall image
A long episode is often a single very tall image. Because software and services have limits on file size and image height, the episode is typically cut into several segments that are stacked on top of each other when displayed. The cuts should be invisible to the reader.
Good slicing follows a few habits:
- Cut in the gaps between panels, where the background is plain or empty, not through a face, a speech bubble or a line of text.
- Make sure segments line up exactly, with no visible seam or color shift.
- Keep each segment within the size limits of your platform.
If the exact cut falls awkwardly, it is better to adjust the layout slightly than to hope the break goes unnoticed. This is part of planning layout around the technical limits, and it is one reason many creators think about file structure early. The mechanics of exporting are covered more fully under file preparation.
File weight and loading
Large images take longer to load, especially on slower connections or older phones. A heavy episode may load in pieces, with the reader seeing blank space while later segments arrive. This can interrupt the flow and make suspense or timing fall apart.
Some general practices help:
- Use an appropriate file format and compression setting for the kind of art. Flat colors and clean lines compress differently from detailed painted work.
- Avoid unnecessary extra resolution.
- Test a finished episode on a real phone, ideally with a modest connection.
There is a trade-off between quality and size, and the right balance depends on your art style and audience.
Length and pacing
Length is tied to pacing, which is how time and tension are spread through an episode. A short episode with a tight structure can feel full. A long one with long empty stretches can feel slow. The spacing between panels contributes to this. Wide gaps add length without adding story, and that can be exactly what a quiet moment needs, but used unthinkingly it makes an episode feel stretched. The use of gutter space is covered in a separate article.
Think also about where readers stop. An episode that ends neatly at a natural break feels satisfying. One that ends mid-scene for no reason may feel arbitrary, unless it is a deliberate hook, a topic covered in the article on cliffhanger endings.
A practical approach for beginners
If you are starting out, a sensible path is:
- Check the recommended canvas width and file limits for your intended platform.
- Plan a modest episode length you are confident you can finish on time.
- Sketch the whole episode in thumbnails and see how tall it will be.
- Decide where the cut points will fall before drawing finished art.
- Export a test and view it on a phone.
Over time you will learn what length suits your story and your pace. It is fine to adjust as you go. Many creators change their typical length after a few episodes, once they see what works for them and for readers.