The Format Decision
In premium colour, Amazon charges a flat printing cost for a paperback of 24 to 40 pages. At 42 pages the formula changes and every page starts costing money. A 24-page picture book and a 40-page picture book cost the same to print. A 48-page one does not.
Format is not a finishing decision. Trim size and page count set printing cost, printing cost sets the lowest price you are allowed to charge, and that floor decides which royalty band you can reach at all. Decide it after the art is drawn and the arithmetic may already be lost.
This is a working reference for anyone publishing an illustrated or short-form title: the printing-cost formulas and where they step, the royalty bands and the opt-in nobody mentions, the minimum page counts, and what reflowable versus print-replica actually costs you in reach.
Every rate carries the date it was checked. Rates move; check yours.
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