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Covers and templates

Page templates

Templates live in the bubble package under templates/. Pass --template or set "template" in peanut.config.

Template Trim size Typical use
amazon_7x10.tpl 7×10 in Default — Amazon KDP color
lulu_7x10.tpl 7×10 in Lulu paperback/hardcover
amazon_6x9.tpl 6×9 in Amazon smaller trim
lulu_6x9.tpl 6×9 in Lulu 6×9
amazon_5.5x8.5.tpl 5.5×8.5 in Mass-market paperback
lulu_5.5x8.5.tpl 5.5×8.5 in Lulu digest
a4_8.5x11.tpl 8.5×11 in US letter / large format

bubble-build and bubble-convert default to amazon_7x10.tpl when no template is set.

Cover folder selection

Template choice maps to a default cover directory:

Template Default cover folder
lulu_7x10.tpl, amazon_7x10.tpl cover/7x10/
a4_8.5x11.tpl cover/8.5x11/

Override with --cover:

bubble-build --cover 7x10-packt
bubble-build --cover 7x10
bubble-build --cover 8.5x11

Cover PDF resolution order

For cover_front.pdf / cover_back.pdf:

  1. cover/{cover_folder}/cover_front.pdf
  2. cover/cover_front.pdf (legacy)
  3. cover_front.pdf in project root

Regenerating covers

Before using cover PDFs, bubble-build runs Python scripts in the active cover folder (e.g. cover_front.py, cover_back.py, or v2 draw scripts) so PDFs match the chosen size and provider.

Cover provider examples (for full-wrap scripts):

bubble-batch en --cover 7x10 --cover-provider kdp/paperback
bubble-batch all --cover-provider ingram/hardcover --cover-version v2

Aliases include kdp_paperback, ingram_hardcover, lulu_paperback, lulu_hardcover.

Print dimensions and Python helpers (bubble.cover_print, bubble.cover_draw, …) are documented in Cover rendering API.

Chapter styles

Style Appearance
circle Quarter-circle chapter number (default in many configs)
square Blue square chapter number
none No decoration — typical for KDP/print interior uploads 
bubble-build --style square
bubble-build --style circle --chapter-opener-size 5
bubble-build --no-cover --style none    # interior-only PDF

chapter_opener_size_cm in peanut.config (default 4) sets the badge size when CLI omits --chapter-opener-size. The numeral font scales with badge size.

PDF size optimization

bubble-build --optimize-pdf
bubble-build --optimize-pdf --optimize-pdf-quality prepress   # English: less aggressive GS
  • English / Spanish: Ghostscript pdfwrite (requires gs)
  • CJK: qpdf --optimize-images (requires qpdf; avoids breaking XeLaTeX outlines)

Protection vs size

--protect rasterizes pages (default 300 DPI), producing large PDFs. For POD uploads prefer --optimize-pdf without --protect, or lower --protect-dpi.

Proposal / query letter layout

bubble-proposal uses templates/proposal_book_style.tex — U.S. nonfiction proposal conventions (title page, running header, double-spaced body). YAML front matter in the Markdown can set title, subtitle, author, runtitle, runlastname, etc.

bubble-proposal querytracker/proposal.md --lang en --optimize-pdf

For business plans (bubble-bizplan, peanut-biz.config), see Business plans.

For academic papers (bubble-paper, templates/paper_style.tex), see Academic papers.