Paper weight, or GSM
GSM means grams per square metre. It is the weight of a sheet one metre square, and it is the closest thing the trade has to a single number for how substantial a paper feels.
For the inside pages of a book, most novels and non-fiction sit between 70 and 100 GSM. Below 70 the page starts to show print from the other side — what printers call show-through. Above 100 a long book becomes a brick, and the spine has to grow to hold it.
Children's books and anything with photographs usually go heavier, 120 GSM and up, because ink coverage is high and thin paper buckles under it.
- 70–80 GSM — novels, long non-fiction. Light in the hand, economical to post.
- 90–100 GSM — a more substantial feel, and safer if your book has illustrations.
- 120–170 GSM — picture books, art books, anything with full-page colour.
- 250–350 GSM — covers, not interiors.
Natural shade or white
Natural shade — sometimes called cream, ivory or off-white — is slightly yellow. White is white. The difference sounds trivial and is not.
Natural shade is easier on the eye over a long reading session, because the contrast between ink and page is gentler. It is the standard for fiction and most narrative non-fiction, and it reads as warmer and more literary.
White gives you sharper contrast and truer colour. Anything with photographs, diagrams, or colour illustration should be on white — natural shade will tint every image on the page.
Binding
Binding is how the pages are held together, and it sets both the durability and the price of your book.
- Perfect binding — pages glued to a wrap-around cover, giving the flat printed spine you see on most paperbacks. The default for anything over about 60 pages.
- Saddle stitch — folded sheets stapled through the fold. Cheap and flat-opening, but only works up to roughly 48 pages and has no printable spine.
- Case binding (hardback) — pages sewn into sections and glued into a rigid board cover. Expensive, heavy, and the only choice that survives a library.
- Spiral or wire-o — lies completely flat. Right for workbooks, cookbooks and anything someone has to use with their hands full.
Cover finish: matt or gloss
Lamination is the thin film over your printed cover. It stops the cover scuffing, and it changes how the book looks under light.
Matt lamination is non-reflective and soft to the touch. Colours sit slightly muted and deep, which suits literary fiction, memoir and anything restrained. It marks more easily — fingerprints and scuffs show on dark matt covers.
Gloss lamination is reflective. Colour looks brighter and more saturated, and it wipes clean. It is the standard for children's books, commercial fiction and anything that has to shout from a shelf.
- Matt — literary, quiet, tactile. Shows fingerprints on dark covers.
- Gloss — bright, hard-wearing, easy to clean. Reads as commercial.
- Soft-touch matt — a velvety finish at a premium price. Beautiful and easily marked.
- Spot UV — gloss varnish on selected areas of a matt cover, usually the title. Adds cost and a great deal of presence.
What to send the printer
Two PDFs: one for the interior, one for the cover, both with fonts embedded so nothing is substituted on a machine that has never heard of your typeface.
The interior needs bleed if any element runs to the edge of the page, and a gutter margin wide enough that text does not disappear into the spine — the thicker the book, the wider that needs to be.
The cover is a single flat spread: back cover, spine, front cover, in that order, sized to the exact spine width your page count and paper produce. Get the paper decision wrong and the spine width changes, and the cover no longer fits.