Usage
Momovu provides a comprehensive set of tools for previewing and analyzing PDF margins. This guide covers all features, command-line options, and keyboard shortcuts.
Quick Start
Basic usage:
# Open a PDF file
momovu document.pdf

Basic momovu window with interior PDF
# Specify document type and page count
momovu -d cover -n 300 book.pdf
# Enable side-by-side view for interior documents
momovu -s interior.pdf
Command Line Interface
Synopsis
momovu [-h] [-D] [-v] [-V] [-n N] [-d TYPE] [-j PAGE] [-s] [-m | --safety-margins | --no-safety-margins]
[-t | --trim-lines | --no-trim-lines] [-b | --barcode | --no-barcode]
[-l | --fold-lines | --no-fold-lines] [-r | --bleed-lines | --no-bleed-lines]
[-u | --gutter | --no-gutter] [-p] [-f]
[PDF_FILE]
Arguments
Positional Arguments:
PDF_FILE
- Path to the PDF file to preview (optional)
Optional Arguments:
-h, --help
- Show help message and exit-D, --debug
- Enable debug logging for troubleshooting-v, --verbose
- Increase output verbosity (can be used multiple times: -v, -vv, -vvv)-V, --version
- Show version information and exit-n N, --num-pages N
- Number of pages for spine width calculation-d TYPE, --document TYPE
- Document type: interior, cover, or dustjacket (default: interior)-j PAGE, --jump PAGE
- Jump to page number (interior documents only)-s, --side-by-side
- Start in side-by-side view mode (interior documents only)-m, --safety-margins, --no-safety-margins
- Show safety margins (default: enabled)-t, --trim-lines, --no-trim-lines
- Show trim lines (default: enabled)-b, --barcode, --no-barcode
- Show barcode area for cover/dustjacket (default: enabled)-l, --fold-lines, --no-fold-lines
- Show fold lines for cover/dustjacket (default: enabled)-r, --bleed-lines, --no-bleed-lines
- Show bleed lines for cover/dustjacket (default: enabled)-u, --gutter, --no-gutter
- Show gutter margin for interior documents (default: enabled)-p, --presentation
- Start in presentation mode-f, --fullscreen
- Start in fullscreen mode
Examples
# Preview an interior PDF with default settings
momovu book-interior.pdf
# Preview a cover with 300 pages (affects spine width)
momovu -d cover -n 300 book-cover.pdf
# Preview a dustjacket with specific page count
momovu -d dustjacket -n 442 book-dustjacket.pdf
# View interior pages in side-by-side mode
momovu -s book-interior.pdf
# Jump to a specific page in an interior document
momovu -j 50 book-interior.pdf
# Combine jump with side-by-side view
momovu -j 100 -s book-interior.pdf
# View interior pages without gutter margins
momovu --no-gutter book-interior.pdf
# Enable debug logging for troubleshooting
momovu --debug problematic-file.pdf
# Increase verbosity for more detailed output
momovu -vv document.pdf
Keyboard Shortcuts
View Controls
Ctrl+Plus/=
- Zoom in (10% increment)Ctrl+Minus
- Zoom out (10% decrement)Ctrl+0
- Fit page to windowCtrl+Mouse Wheel
- Zoom in/out at mouse cursor positionCtrl+I
- Open Font Information window

Zoomed in view showing detail of the page content with high-quality rendering
F11
- Toggle fullscreen modeF5
- Toggle presentation modeEscape
- Exit presentation mode
Zoom and Pan Behavior
When zoomed out (fit to page):
Mouse Wheel
- Navigate between pagesCtrl+Mouse Wheel
- Zoom in/out at cursor position
When zoomed in:
Mouse Wheel
- Pan vertically (scroll up/down)Shift+Mouse Wheel
- Pan horizontally (scroll left/right)Ctrl+Mouse Wheel
- Zoom in/out at cursor positionArrow Keys
- Pan in any direction
The zoom system features:
High-quality rendering at all zoom levels (up to 200x)
Progressive rendering for smooth zoom experience
Intelligent caching for instant panning
Mouse-centered zoom for precise control
Display Options
Ctrl+D
- Toggle side-by-side view (interior documents only)Ctrl+T
- Toggle trim lines visibilityCtrl+M
- Toggle safety margins visibilityCtrl+L
- Toggle spine/fold lines visibilityCtrl+B
- Toggle barcode area (cover/dustjacket only)Ctrl+R
- Toggle bleed lines (cover/dustjacket only)Ctrl+U
- Toggle gutter margin (interior only)
File Operations
Ctrl+O
- Open a new PDF fileCtrl+W
- Close current documentCtrl+G
- Go to page dialogCtrl+I
- Font Information windowCtrl+Q
- Quit application
Text Selection and Copying
Click and Drag
- Select text with mouseCtrl+C
- Copy selected text to clipboard
Document Types
Interior Documents
Interior documents represent the content pages of a book:
Simple rectangular safety margins
Gutter margins that automatically adjust based on page count
Side-by-side view available for spread preview
Spine line visible in dual-page mode
Navigation to first/last page enabled
momovu -d interior book-content.pdf
# With side-by-side view
momovu -d interior -s book-content.pdf

Interior document displayed in single page view mode
Cover Documents
Cover documents include front and back covers with spine:
Spine width automatically calculated from page count
Barcode placement area in lower right of back cover
Fold lines at spine edges (green dashed lines)
Safety margins with bleed areas
momovu -d cover -n 300 book-cover.pdf

Cover document with automatically calculated spine width based on page count

Cover document showing safety margins and bleed areas
Spine Width Calculation:
Default formula (Lulu): (pages / 17.48) + 1.524 mm
Alternative formulas available for Lightning Source with various paper weights
Select your preferred printer in File → Preferences → Formulas tab
Converted to points for display
Example: 300 pages = 18.69 mm spine width (using Lulu formula)
Note: These formulas are approximations - verify with your printer’s official tools
Dustjacket Documents
Dustjackets include covers, spine, and flaps:
Complete dustjacket layout visualization
Fixed flap dimensions: 3.25” x 9” (82.55mm x 228.6mm)
Multiple fold lines for all edges
Separate margins for flaps and covers
momovu -d dustjacket -n 500 book-dustjacket.pdf

Complete dustjacket layout with flaps, spine, fold lines, and bleed lines visible

Dustjacket showing bleed lines that extend beyond trim lines for print production
Presentation Mode
Presentation mode provides a distraction-free view:
Full-screen display without UI elements
Maintains current view mode and overlays
Smooth page-by-page navigation
Exit with F5 or Escape
Navigation in presentation mode:
Page Down
orSpace
- Next pagePage Up
orBackspace
- Previous pageArrow Keys
- Pan view if zoomedF5
orEscape
- Exit presentation mode

Presentation mode showing pages in fullscreen without any UI elements
Starting presentation mode:
Press
F5
while viewing a documentAll overlay toggles remain functional
Fullscreen Mode
Fullscreen mode maximizes the window:
Window fills entire screen
Menus and toolbars remain accessible
Different from presentation mode
Toggle with
F11

Fullscreen mode with maximized window while keeping menus and toolbars visible
Side-by-Side View
Side-by-side view displays interior pages as spreads:
First page displayed alone (right side)
Subsequent pages in proper left/right pairs
Spine line visualization between pages
Maintains reading order
Toggle with Ctrl+D
or via View menu (interior documents only).

Interior pages displayed as a book spread in side-by-side view
Visual Overlays

All visual overlays enabled together showing trim lines, safety margins, fold lines, barcode area, and bleed lines
Safety Margins
Safety margins indicate the safe content area:
Appearance: Semi-transparent blue/purple overlay (#7F7FC1)
Default Size: 12.7mm (0.5 inches)
Purpose: Show printable area safe from trimming
Toggle:
Ctrl+M

Safety margins overlay showing the safe content area
Trim Lines
Trim lines show where pages will be cut:
Appearance: Black solid lines at edges
Purpose: Indicate final page dimensions
Essential for: Bleed verification
Toggle:
Ctrl+T

Trim lines showing where the page will be cut
Spine/Fold Lines
Document-specific spine indicators:
Interior Documents:
* Center spine line in side-by-side view
* Purple solid line between page pairs
* Toggle: Ctrl+L
Cover Documents:
* Fold lines at spine edges
* Purple dashed lines
* Based on calculated spine width
* Toggle: Ctrl+L
Dustjacket Documents:
* Multiple fold lines for all edges
* Purple dashed lines for all folds
* Separate margins for flaps (teal) and spine (olive)
* Toggle: Ctrl+L

Spine and fold lines indicating where the cover will be folded
Barcode Area
Barcode placement indicator:
Location: Lower right of back cover
Appearance: Orange dash-dot rectangle with “BARCODE” label
Documents: Cover and dustjacket only
Toggle:
Ctrl+B

Barcode placement area on the back cover
Bleed Lines
Bleed lines show the actual page edges for cover and dustjacket documents:
Appearance: Light blue solid lines (#22b5f0) at page edges
Purpose: Show actual page boundaries (outside trim lines)
Documents: Cover and dustjacket only
Toggle:
Ctrl+R
Bleed lines appear at the actual page edges, while trim lines appear inside at the bleed offset: * Cover documents: 3.18mm (1/8”) bleed * Dustjacket documents: 6.35mm (1/4”) bleed

Bleed lines showing the actual page edges for print production
Gutter Margins
Gutter margins provide additional space for binding:
Appearance: Semi-transparent green overlay (#79C196)
Purpose: Account for binding space that reduces usable page area
Documents: Interior only
Toggle:
Ctrl+U
Gutter width automatically adjusts based on page count:
Less than 60 pages: No gutter needed
61-150 pages: 1.5mm per page (3mm total for both pages)
151-400 pages: 6.5mm per page (13mm total)
401-600 pages: 8mm per page (16mm total)
Over 600 pages: 9.5mm per page (19mm total)
The gutter appears on the spine side of each page:
Left pages: Gutter on right side
Right pages: Gutter on left side
Single page view: Gutter on left side (like a right page)

Gutter margins (green) with safety margins (blue) in side-by-side view, showing how gutter extends inward from safety margins toward the spine
Copying Text from PDFs
Momovu allows you to select and copy text from PDF documents:
Selecting Text
Click and drag with your mouse to select text
Blue highlight appears over selected text
Copying Selected Text
Once text is selected, you can copy it:
Ctrl+C to copy selected text to clipboard
Edit → Copy menu option also available
The Copy action is only enabled when text is selected
Important Notes
The blue selection highlight provides visual feedback of what will be copied
Text selection is cleared when changing pages or documents
Find Text
Quickly locate specific text within your documents:
Open Find - Press Ctrl+F or use Edit → Find… menu
Search - Type your text in the search box that appears at the top of the window
Navigate results - Use F3 for next match or Shift+F3 for previous match
Visual indicators - All matches are highlighted in yellow, with the current match highlighted in orange
Search options - Toggle case sensitive, whole words, or regular expression searches using the buttons
Close Find - Press Escape or click the X button to close the search bar
The blue selection highlight provides visual feedback of what will be copied
Text selection is cleared when changing pages or documents
Go to Page Dialog
Quick page navigation:
Open: Ctrl+G or View → Go to Page…
Features: - Shows current page and total pages - Input validation - Enter key navigates - Escape key cancels
Sample Files
The repository includes sample PDFs for testing:
# Interior document examples
momovu -d interior samples/bovary-interior.pdf
momovu -d interior -s samples/pingouins-interior.pdf
# Jump to specific pages in interior documents
momovu -d interior -j 50 samples/bovary-interior.pdf
momovu -d interior -j 100 -s samples/pingouins-interior.pdf
# Cover examples with different page counts
momovu -d cover -n 688 samples/bovary-cover.pdf
momovu -d cover -n 126 samples/lovecraft-cover.pdf
momovu -d cover -n 574 samples/pingouins-cover.pdf
momovu -d cover -n 180 samples/quixote-cover.pdf
momovu -d cover -n 100 samples/siddhartha-cover.pdf
momovu -d cover -n 442 samples/vatican-cover.pdf
# Dustjacket examples
momovu -d dustjacket -n 688 samples/bovary-dustjacket.pdf
momovu -d dustjacket -n 574 samples/pingouins-dustjacket.pdf
momovu -d dustjacket -n 442 samples/vatican-dustjacket.pdf