Paper choice changes your cover

Three stocks, three thicknesses

KDP offers white and cream paper for black-and-white interiors and a colour stock for colour printing. Each has a different thickness per page, and spine width is calculated from that thickness. These are the figures this app uses:

• White: 0.002252" per page. Standard white stock for text-heavy books.
• Cream: 0.0025" per page. Warmer stock, common for fiction and journals.
• Colour: 0.002347" per page. Colour printing stock for illustrated interiors.

What changing paper does to a cover

At 200 pages, the spine is 0.450" on white, 0.469" on colour and 0.500" on cream. The difference looks small, but the spine sits in the middle of the cover, so every element on the front panel moves when it changes. A cover built for white paper and uploaded for a cream-paper book has its front panel off-centre and its spine text near a fold.

Choosing between white and cream

This is a matter of taste and convention rather than a rule. Cream is widely used for fiction and long-form reading because it is softer on the eye; white is common for non-fiction, workbooks and anything with photographs or diagrams, where contrast matters. Look at comparable books in your genre.

Whichever you choose, decide before the cover is finished, and recalculate after any change to page count or paper.

Paper and print cost

Paper choice also interacts with ink. White and cream are offered for black-and-white printing; colour interiors use the colour stock and cost more to print per page. A book with only a few colour images may be cheaper to print in black and white with the images converted to greyscale — a decision worth making before the cover is designed, because it changes the paper and therefore the spine.

KDP's printing-cost calculator, in your bookshelf and help pages, shows what each combination costs for your page count and trim. Check it alongside the spine width before you commit.