Print on demand removed the part of publishing that used to need money: a garage full of books you had already paid for. The trade is a higher cost per copy and a thinner margin, and the arithmetic is worth doing before you design anything.
How it works
You upload two files: an interior PDF and a cover PDF. A reader orders. The printer produces that single copy, ships it, takes the print cost and a commission, and pays you the rest.
No stock, no minimum, no warehouse. The cost is per copy and it does not fall with volume the way an offset print run does. That is the whole difference from traditional printing, and the reason a POD paperback margin is what it is.
The three that matter
| KDP Print | IngramSpark | Lulu | |
|---|---|---|---|
| Reach | Amazon, dominant | Bookshops, libraries, Amazon | Direct sales, some retail |
| Setup cost | Free | Small fee, often waived | Free |
| Royalty on Amazon | Best | Lower, after wholesale discount | Lower |
| Bookshop distribution | No | Yes, the reason to use it | Limited |
| Returns handling | N/A | Configurable, and it matters | N/A |
| Hardcover | Yes | Yes, more options | Yes, most options |
| Best for | Amazon sales | Everywhere that is not Amazon | Selling from your own site |
KDP Print is the default and should be. It is free, it is where most self-published paperbacks sell, and the royalty is the best available on Amazon. If you only ever do one, do this one.
IngramSpark exists for the thing KDP cannot do: getting your book into a catalogue that bookshops and libraries order from. A shop will generally not order from Amazon. If a physical shop stocking the book matters, this is not optional. And Draft2Digital vs KDP makes the same both-not-either argument on the ebook side.
Lulu is strongest for selling direct from your own storefront, with the widest format range including unusual sizes and premium bindings.
Using KDP Print for Amazon and IngramSpark for the rest is the standard arrangement. If you do that, do not enable IngramSpark's Amazon distribution as well, or the two compete to supply the same listing.
The arithmetic
One calculation decides whether a price works.
Your price − print cost − the retailer's cut = your royalty.
Print cost is driven mostly by page count and whether the interior is black and white or colour. Colour is dramatically more expensive and turns a viable book into an unviable one faster than any other decision.
| Book | Typical shape | Result |
|---|---|---|
| 200-page B&W paperback | Low print cost | Comfortable margin at a normal price |
| 400-page B&W paperback | Roughly double | Needs a higher price |
| 100-page colour interior | Very high print cost | Often prices itself out |
| Hardcover | Higher again | Works as a premium edition |
Two practical consequences. Page count is a commercial decision, not only an editorial one, and it is set by trim size, margins and type size as much as by word count, which is what word count to page count and page margins and line length are really deciding. And if your book needs colour throughout, consider whether it should be an ebook or a PDF instead; EPUB or PDF covers that choice.
Run the numbers in each platform's own printing calculator before setting a price. What it actually costs to self-publish a book covers the costs that sit around this one.
What the files have to be
This is where most first uploads fail, and the requirements are stricter than for an ebook.
- A print-ready PDF, with fonts embedded and images at print resolution. What makes a PDF print-ready is the checklist, and why your PDF looks wrong on someone else's computer is the failure it prevents.
- The correct trim size, chosen before formatting rather than after: A4, Letter or a trim size.
- Margins that respect the gutter. The inner margin must be larger, because the binding eats it, and the minimum grows with page count.
- A cover built on the printer's own template, which depends on your final page count because the spine width does. Spine width, bleed and the print cover template covers it. The cover cannot be finished until the interior is.
- An ISBN. KDP will assign a free one; IngramSpark requires your own. If you want the book under your own imprint, buy one: do you need an ISBN.
Where bukpress fits, and where it does not
bukpress produces the interior: a typeset PDF from a Markdown manuscript, with margins in points, controlled line height and typography that holds up in print, plus the reflowable EPUB from the same source for the ebook edition.
The honest limit, stated plainly because it decides whether this is for you: pages are A4. That suits workbooks, manuals, handbooks, course material and non-fiction sold direct or printed at A4. It is not a 6 × 9 novel interior laid out for a press. If your book is a novel going to KDP Print at a standard trim, book formatting software covers the tools built for that, and Vellum or Atticus is the better recommendation.
What it does remove is maintaining two manuscripts: the print interior and the ebook come from one Markdown source, so a correction is one edit and one rebuild. The sample book is eight pages of the output, and from Markdown draft to published book is the whole route.
Common questions
Is print on demand worth it for books?
For self-publishers, almost always: it removes stock risk entirely. The margin per copy is thinner than an offset run, which only becomes the better deal at volumes most self-published books never reach.
What is the best print on demand for books?
KDP Print for Amazon sales, IngramSpark for bookshop and library distribution, Lulu for selling direct from your own site. Using KDP and IngramSpark together is the common arrangement.
How much does print on demand cost?
Nothing upfront on KDP Print and Lulu; IngramSpark charges a small setup fee that is often waived. The real cost is per copy, driven by page count and whether the interior is colour.
Do I need an ISBN for print on demand?
KDP will assign one free. IngramSpark requires your own. Buy one if you want the book listed under your own imprint rather than the platform's.
Can I use the same PDF for print and ebook?
No. Print needs a fixed-layout, print-ready PDF at a specific trim size; an ebook should be a reflowable EPUB. Produce both from one manuscript rather than converting one into the other.