Lumi-o

Lumi is developed in the open, with design decisions, architecture documents, and development history publicly available so users can understand how the software evolves over time.

It prioritizes long-term accessibility of artwork. The file format is open, directory-based, and readable without proprietary software, ensuring projects remain accessible as the software continues to change. Compatibility is supported through XCF and PSD import and export.

Lumi is designed to be understandable as well as powerful. The interface reduces unnecessary complexity, keeping the workspace focused on painting and drawing.

Purpose

Lumi exists to support a structured method of illustration developed through years of practice, providing a reliable tool for complex, non-destructive workflows where color, layers, and data behave predictably.

It is shared freely for others to use and explore. Lumi is not a catch-all solution, but a focused and opinionated tool shaped by real experience with traditional media and complex software systems. Lumi treats toolmaking as a craft: something to understand, shape, and share openly without subscriptions, lock-in, or cloud-dependent features.

Lumi addresses a gap between general image editors and dedicated painting software. It remains free and open source, avoids AI-driven generation features within the application itself, and removes photography-oriented design constraints while retaining the power and reliability of the GIMP architecture.

The result is a painting-focused environment built for deliberate, manual image making rather than automated production. Reliability is a core feature: autosave, fast saving, and incremental saving are built into the workflow from the beginning. The Lumi file format is open and highly efficient, using lazy loading so very large projects open quickly and remain responsive during long illustration sessions.

Lumi is designed for artists who expect their tools to remain stable, transparent, and under their control over years of work.

Artistic Foundation

Lumi is developed by an independent artist with decades of experience spanning pixel art, traditional drawing and painting, and professional work in game development, technical art, illustration, and 3D animation.

This combination of artistic practice and technical implementation directly shapes Lumi’s design, influencing its approach to color, linework, layers, performance, data recovery, scripting, and user experience.

The Philosophy

Lumi combines a pigment-based color system built around physical mixing with a highly responsive, non-destructive, layer-based illustration workflow.

• Pigment-Centric: Colors are derived from real-world pigment profiles (Colour Index codes) rather than arbitrary RGB values, supporting intuitive palette construction grounded in real painting experience.
• Tactile Tools: Brushes, stylus pressure, tilt, and velocity are fully integrated to behave like physical painting tools, giving nuanced control with minimal friction.
• Scene Management: Layered, non-destructive workflows scale in complexity while remaining predictable and responsive.
• Intent-Focused Controls: Tools offer meaningful options without overwhelming the artist, supporting deliberate, skill-driven decisions.

What the Software Prioritizes

• Artistic Intent: Tools behave predictably and support the artist’s intuition.
• Reliability: Data integrity and recovery are paramount; an artist should never lose work.
• Structural Clarity: The interface keeps layers, tools, and file formats straightforward and readable, so even large paintings with hundreds of layers remain manageable.

It Is Not

• A General Purpose Image Editor: Lumi is not intended for photo retouching, web design, or desktop publishing.
• A Multi-Platform Tool: Lumi is optimized specifically for Linux and does not support Windows or macOS.

Future Releases

Features evolve rapidly during development, but releases are made only after sustained use in real-world illustration workflows. Lumi is used daily in the creator’s own artwork and production projects, with development guided by needs discovered through that practice. Toolmaking and artmaking are treated as a single ongoing discipline.

Lumi is developed with AI-assisted development tools as part of the engineering process. After many years of manual development, AI systems are now used to help refactor code, explore architectural changes, and accelerate implementation while maintaining human direction and final responsibility for design decisions. As AI development tools continue to mature, they are expected to improve the sustainability and evolution of the project rather than replace artistic authorship. Lumi applies automation to building tools, not to replacing the act of painting.

Acknowledgments

Lumi is built on the foundation of the GNU Image Manipulation Program (GIMP). Lumi acknowledges and is deeply grateful for the many years of work by the developers, artists, and contributors.