Trim Sizes & Page Margins

Configure your book’s physical dimensions and page margins for print-on-demand publishing. Both panels live under Print Settings in the Page Setup group: Trim Size and Margins. Pair these with book page layout and fonts for body typography and book headers and footers for running heads.

Trim Sizes

The Trim Size panel offers 18 standard print-on-demand sizes, grouped by width, with a toggle to view them in inches (in) or millimeters (mm):

Pocket & Small

4” × 6”4.25” × 6.87”4.25” × 7”4.37” × 7”4.5” × 7”

Standard

5” × 8”5.06” × 7.81”5.25” × 8”5.5” × 8.5”6” × 9”6.14” × 9.21”

Large & Specialty

6.69” × 9.61”7” × 10”7.44” × 9.69”7.5” × 9.25”8” × 8”8” × 10”8.5” × 11”

Custom Trim Size

Printing at a size that isn’t on the list? Turn on Custom Size (“Set an exact width and height”) to enter your own dimensions.

1. Toggle Custom Size on. The preset grid swaps to Width and Height fields.
2. Enter your dimensions, in inches or millimeters depending on the unit toggle at the top of the panel. Each side can be from 3 to 12 inches (about 76 to 305 mm).
3. Click Apply.

Tip

Check your printer’s spec sheet before committing to a custom size. Print-on-demand services accept custom trim sizes, but distribution options can be narrower than for the standard sizes above.

Page Margins

The Print Page Margins panel separates two things that used to share one number: what your printer requires, and what you choose for your design. It has four tabs: Safe Zone, Content, Header, and Footer.

• The safe zone is the minimum distance your printer requires between the trimmed page edge and anything on the page. This is the distributor’s number.
• Content spacing is the extra room you add inside the safe zone. This is your design decision: breathing room that shapes how the page looks, on top of what the printer demands.

Coming from an earlier version of Lacuna?

Books saved before this panel existed carry over automatically. Your margins open as the equivalent safe zone and content values, and your pages print exactly as before.

See the zones while you adjust them

Click the Margin Guidelines button in the panel’s tab bar to draw the safe zone, content zone, and header and footer bands right onto the print preview. With the guides on, every value you change moves a visible line on the page.

Safe Zone

Two values define the boundary your distributor asks for:

• Inside (gutter). The binding edge. It needs more room as the page count grows, because a thicker book curves further into the spine.
• Outside (all other edges). The top, bottom, and outer edges. They share one distributor minimum, so editing this moves all three together.

Distributors recommend keeping content at least 0.25 inches from the trimmed edge. Lacuna shows a warning if you go below that, but never blocks you.

Distributor Suggestions

Below the safe zone fields, a suggestion card checks your values against real distributor requirements for your book’s current page count. Pick Amazon KDP, IngramSpark, or Lulu and the card shows each minimum, marks whether your safe zone meets it, and offers Use suggested to snap to the recommendation in one click.

The safe zone alone has to cover these minimums. Space you add on the Content, Header, and Footer tabs is breathing room on top of the safe zone, so it does not count toward them.

Bleed

When your book has background images, full-page images, or printed edges that run to the paper’s edge, the bleed settings control the extra area the printer trims away:

• Amount. A typical bleed is 0.125 in or 3 mm. BookVault asks for 3 mm. If you are not sure what your printer wants, use 0.125 in.
• Edges. Most printers (Amazon KDP, IngramSpark) trim the binding edge flush and want bleed on the Three outer edges. Some printers, like BookVault, ask for bleed on All four edges, including the binding side.

Content

The Content tab adds space inside the safe zone, with its own Inside (gutter) and Outside (all other edges) values. Use it to give your text block more air than the bare minimum: wider outer margins for a classic look, or a roomier gutter for a thick book.

Header and Footer Spacing

The Header and Footer tabs shape the bands your page numbers and running titles sit in:

• Total Space. The full distance from the safety line down to where body text begins (or up from it, for the footer). This controls how much room the header or footer area takes up.
• Space Above Header / Space Below Footer. Pushes the header or footer itself away from the safety line. Zero keeps it at the safety line; larger values push it toward the body text.

With trim and margins set, export a print-ready PDF for KDP and IngramSpark.