Print on Demand Explained: KDP, IngramSpark, or Both?

Print on demand means a book is printed only when someone orders it, one copy at a time, with no inventory to buy up front. For self-publishers the two main routes are Amazon KDP and IngramSpark. Many authors use both: KDP for direct Amazon sales, IngramSpark for bookstores, libraries, and international retailers. The route you choose shapes your ISBN decision, so it pays to plan before the first upload.

How print on demand actually works

Before digital printing, putting a book into print meant ordering hundreds or thousands of copies, paying for them in advance, and storing them. Print on demand replaced that with a simple idea: you upload two files, an interior and a cover, and the printer holds them in a database. When a reader orders, the printer produces exactly one copy, binds it, and ships it. No warehouse, no upfront print run, no boxes in your garage.

The tradeoff is unit cost. A single POD copy costs more to make than a copy from a large offset run, so the per-book margin is thinner than bulk printing. What you gain is no risk and no inventory. You can keep a book in print indefinitely, sell one copy a month or a thousand, and never front the cost of stock. For most self-publishers that trade is well worth it.

Follow the money

Here is the flow, simplified. A reader buys your book from a retailer. The retailer sends the order to the print-on-demand supplier. The supplier prints and ships the copy, deducts its printing cost, and passes the rest to you as your share, minus the wholesale discount the retailer keeps. You set the list price and, on the wider-distribution channels, the discount you offer the trade. Understanding that chain is what lets you price a book so it actually earns after production and the retailer's cut.

KDP, IngramSpark, or both

The two platforms are not rivals so much as different doors.

• Amazon KDP is the direct door to Amazon, where most self-published sales happen. It is forgiving about files, offers a free ISBN option, and adds a barcode for you. If Amazon is your whole plan, KDP alone is enough.
• IngramSpark feeds the Ingram catalog, which is how physical bookstores, libraries, and international and online retailers order books. It requires your own ISBN and stricter print files, and it eliminated title setup fees in 2023.

The common wide-distribution setup is both: KDP for Amazon, IngramSpark for everywhere else. Many authors let KDP handle Amazon and rely on IngramSpark for the rest of the world rather than routing Amazon sales through Ingram. That keeps your Amazon margin healthy while still making the book orderable at a local shop or a library system.

Whichever route you pick, the finished interior and cover files are the same craft. A professional template gets you a retail-quality book that both platforms accept. If you also want the marketing side handled, our Book Planner Toolkit walks you through production and launch decisions in order.

The ISBN implications of each path

This is the part worth deciding early, because it is hard to undo.

1. KDP only, free ISBN. Simplest and free. The catch is that a free KDP ISBN lists Amazon as the publisher of record and works only on Amazon. It cannot travel to IngramSpark.
2. KDP only, your own ISBN. You buy an ISBN from Bowker (myidentifiers.com in the US) and use it on KDP. Your imprint appears on the record, and you keep the door open to add wider distribution later with the same edition.
3. Both platforms. You must use your own ISBN, because IngramSpark does not accept the free KDP one. Buy your ISBN first, then use the same number for that edition on both KDP and IngramSpark so it is recognized as one book.

Remember that each format is its own edition: paperback, hardcover, and ebook each need a separate ISBN. If wide distribution is anywhere in your plan, buy your own ISBN before the first upload. Changing an ISBN after release means setting up a new title and losing the listing history attached to the old one.

Which should you choose?

If you want the simplest path and Amazon is your market, start with KDP. If you want your book in bookstores and libraries, add IngramSpark with your own ISBN. If you are unsure, buying your own ISBN and starting on KDP keeps every option open, because you can extend to Ingram later without renaming the edition. The one choice that closes doors is the free KDP ISBN, so make that decision with your eyes open.

Frequently asked questions

Is print on demand lower quality than offset printing?

For text-driven books the difference is small, and a well-designed interior and cover print beautifully on demand. Offset can edge ahead on very large runs and certain color work, but for most self-published titles POD quality is more than good enough for a retail shelf.

Can I sell on both KDP and IngramSpark at the same time?

Yes, and many authors do. Use KDP for Amazon and IngramSpark for wider distribution, with the same self-purchased ISBN on both so the book is recognized as a single edition rather than two separate listings.

Do I need to buy inventory for print on demand?

No. That is the whole point. Copies are printed as orders come in, so you never buy stock in advance. You can still order author copies or proofs for yourself, but you are never obligated to hold inventory.

Prefer to have it done for you? Cantos, the book designer from our team, can produce your print-ready interior and cover in one pass. See your own book first with a free 30-page preview, no credit card required.