First, Pick Your Path: Print, Digital, or Platform
The decision reduces to two questions. Do you want a physical book? If yes, print-on-demand (Path 1) — upfront cost near zero, per-copy economics fixed by the printer. If no: do you want revenue per copy or audience per episode? Revenue points to digital storefronts (Path 2), where you keep 85–95% of each sale but bring your own traffic. Audience points to webcomic platforms (Path 3), where distribution is free and enormous but direct revenue is thin until you're popular. These aren't exclusive — the standard indie playbook is platform for audience, then digital and print editions sold to the audience you built — but your first release should commit to one primary path so the file prep, pricing, and marketing all point the same direction.
Path 1: Print-on-Demand via Amazon KDP
KDP prints and ships single copies on demand, so self-publishing a physical comic book costs nothing upfront: you upload a print-ready PDF, set a price above the print cost floor, and Amazon pays a 60% royalty on list price minus printing for paperback. The setup steps: pick a trim size (US comic standard 6.625×10.25in, or manga-style 5×7.5 / 5.5×8.5), export an interior PDF with bleed at 300 DPI, build a cover PDF sized to page count (spine width grows with pages), order a physical proof before publishing, and check Amazon's current specs on the KDP print guidelines. Color printing costs meaningfully more per page than black-and-white — a 32-page color comic might carry a $4–5 print cost, which forces a $9.99+ list price to leave a margin. Greyscale interiors are the classic indie economy move.
Path 2: Digital Storefronts You Control
Selling a PDF or CBZ directly means near-zero marginal cost and the best revenue split in publishing.
Gumroad and itch.io — the direct route
Both let you sell a downloadable comic with a revenue share you'd never get from a publisher (itch.io even lets you choose the platform's cut). Upload PDF and CBZ, price at the indie-standard $2.99–7.99, and add a pay-what-you-want floor if you're optimizing for reach. The catch is traffic: these stores don't bring readers, they just don't take much from the ones you bring.
Comic-specific storefronts
GlobalComix and DriveThruComics have actual comic-reading audiences and better discovery than a bare Gumroad page, in exchange for a larger cut. They also handle the reader experience (guided view, in-browser reading) that a raw PDF doesn't.
File prep
Digital wants RGB, print wants your files at 300 DPI with bleed — export both from the same master. A CBZ is just ordered page images in a ZIP; it's the format serious digital comic readers prefer, and it costs you one extra export.
Path 3: Webcomic Platforms as the Top of the Funnel
WEBTOON Canvas, Tapas, and GlobalComix's free tier publish your comic to built-in audiences of millions for nothing. Direct pay is modest — ad-share and tipping programs with eligibility thresholds — but that's not really the point: platforms are where unknown comics get discovered, and the audience you accumulate there is what makes Paths 1 and 2 viable later. The trade-offs to check before uploading: exclusivity terms (non-exclusive by default on Canvas and Tapas, but paid programs can change that), format (vertical scroll performs best, so a print-format comic needs re-stacking), and the fact that you're building on rented land — always keep your source files and an off-platform mailing list.
ISBNs, Rights, and the Paperwork Nobody Warns You About
You do not need an ISBN to publish on KDP — Amazon assigns a free ASIN, and KDP can issue a free ISBN that works only within Amazon. You need a purchased ISBN (via Bowker in the US, roughly $125 single or $295 for ten) only if you want the same edition in bookstores and libraries under your own imprint. Copyright in your work exists automatically from creation in most jurisdictions; registration adds enforcement teeth but isn't a publishing prerequisite. If your comic was made with AI assistance, check each tool's commercial-use terms before selling — and keep records of your creative input (scripts, edits, direction), since that human authorship is what current guidance ties rights to.
The Real Budget: From $0 to Shipped
A realistic self-publish budget has exactly three mandatory line items and they can all be zero: production (your time, or an AI comic tool's subscription — Comicory exports KDP-ready print PDFs with bleed and trim built in, which deletes the file-prep step), a proof copy (a few dollars plus shipping), and a storefront (free on every path above). Everything else — purchased ISBN, editor, print run, convention table — is optional acceleration. The honest sequencing for a first book: publish digital first, use the proof-copy stage to catch print issues, and only consider an offset print run once you have demonstrated demand, because a garage full of unsold boxes is the one classic self-publishing mistake that still costs real money.