Mixam: preparing a print order

Ordering spends money, so a person places the order. The agent builds the files, gives the exact cart settings, and checks a screenshot of the cart against the files.

Binding: choose it by page count

Binding	Pages	Use it when
Saddle-stitch (staples)	at most 96, a multiple of 4; the cover counts in the total	Magazine thickness
Perfect bound (PUR)	32+ inside pages, a multiple of 4; the cover is a separate file	Past 96 pp. Still reads as a thick magazine, with a flat spine for type
Wire-O, hardcover	offered	Wire-O reads as a notebook

Decide the binding before laying out: it changes the file set and the page arithmetic.

PUR spine formula

spine = floor(pages / 2 × caliper, to 0.01 in) + 0.01 in, where pages = inside pages only.

• Calipers (inches per leaf, from Mixam's calculator data, read 2026-10): Satin 70 lb Text 0.0035, 80 lb Text 0.004, 100 lb Text 0.005. Cover weight doesn't change the spine on the standard US plants.
• Fitted against 14 live quotes: 112 pp on 80 lb Text → 0.23 in; 152 pp → 0.31 in (confirmed in a cart).
• Some plants quote wider. Express, and Best Value on 130 lb Cover, quote 0.03–0.10 in wider. Always read the spine width off the cart and rebuild the cover if it differs.
• Put spine text only when the spine is ≥ 0.25 in; keep it 0.08 in clear of each fold.

Files

• Format: trim size + 0.125 in bleed on every edge, TrimBox and BleedBox set. sRGB is fine (Mixam converts). No crop marks.
• PUR cover: one page holding the outer spread, back | spine | front. Width = 2 × trim + spine (8.5 × 11 trim at 152 pp → 17.31 × 11.00 in before bleed). Mixam may warn that it's wider than letter; that's expected.
• Several files in one upload: Mixam orders them by the number in the file name (1-cover.pdf, 2-interior.pdf). The words front, back, rear, last and inner are also understood.
• Cover printed on both sides is the cart default. "Full-color printing (front and back)" means Mixam expects inner front and inner back cover artwork; otherwise the proof shows "Artwork missing" on both. Either supply inner-front.pdf and inner-back.pdf (one trim+bleed page each, uploaded with the ⋯ button on each inner-cover slot), or set the cover to print on the outside only.
• Using the inner covers (e.g. contents inside the front, a closing page inside the back) moves pages out of the body. The body must stay a multiple of 4 and the spine changes with it: plan the inner covers before the final build, not after.

Saddle-stitch settings that worked

Custom trim (e.g. 8.375 × 10.875 in — enter the trim, never trim plus bleed), Coated Satin, 100 lb inside pages.

Checking a cart screenshot

Check every line against the files: size and orientation; binding; inside page count; text paper and weight; spine width = the cover file's spine; cover paper, lamination, and whether the inside covers print. Then report the price per copy at each quantity offered — quantity breaks are steep at short runs.