Vellum Technical Specifications

System Requirements

macOS Version

• macOS 13 (Ventura)
• macOS 14 (Sonoma)
• macOS 15 (Sequoia)
• macOS 26 (Tahoe)

CPU Architecture

• Apple Silicon
• Intel

Available Space

≥ 200 MB

Import

Manuscript Format

• DOCX (Word)

Input Image Formats

• GIF
• HEIC
• HEIF
• JPEG
• PDF
• PNG
• PSD
• SVG
• TIFF
• + more

Image Color Spaces

• sRGB (recommended)
• RGB
• Adobe RGB
• P3
• CMYK
• Gray

Ebook Output

File Formats

• EPUB
• MOBI (optional for Kindle)

EPUB Standard Version

• 3.0
• 2.0 (optional for Generic)

Layout

Reflowable

Fonts

Embedded as required

Output Image Formats

• GIF
• JPEG
• PNG (Apple, Google, Kobo only)
• SVG (Apple only)

Output Image Width

Up to 800–1600 px (vendor-dependent)

Image Color Spaces

RGB

DRM

None (can be applied by vendors)

EPUB Conformance

Validated with EPUBCheck

Accessibility Features

• Structural Navigation
• Semantic Roles
• High-Contrast Text
• Alternative Text (user-provided)

Accessibility Conformance

Assessed with Ace by DAISY

Print Output

File Format

PDF/X-1a:2003

ISO Standard

ISO 15930-1

Color Model

CMYK

Output Intent

U.S. Web Coated (SWOP) v2

Fonts

Embedded (subset)

Image Resolution

Up to 300 ppi

Transparency

Flattened

Bleed

Included when necessary

Content Export

Manuscript Formats

• DOCX (Word)
• RTF