Painting bio: A vector-based method for precise G-code generation across scales in biofabrication

This study introduces a standardized approach to generating and assembling G-code for biofabrication, ensuring compatibility and convergence across diverse machines and scales. Using vector-based drawing software, such as Adobe Illustrator, shapes are designed as paths and converted into modular G-code blocks (subroutines). This vector-based approach allows for the straightforward design of complex structures, such as organic shapes, by simply drawing them to scale, avoiding the need for labour-intensive construction. These blocks are assembled into a final script with a modified version of Notepad++ that enhances code segmentation and provides real-time visualization. Unlike many commercial slicers, this method offers precise control over the print path—a critical advantage in biofabrication, where anisotropic structures are essential for directed cell growth and orientation-specific mechanical properties needed in biomimetic tissue design. The method’s versatility is demonstrated across techniques from micro-scale applications, such as melt electrowriting, to macro-scale approaches like bioprinting, freeform printing and in-gel printing. This process streamlines code generation, allowing both simple and complex shapes to be efficiently produced. Although paths are drawn in 2D, stacking layers enables 3D constructs. The method’s standardized, relative G-code format—compatible with most devices—supports easy transfer across machines with clearly marked, machine-specific segments, creating a unified and adaptable codebase for a range of fabrication scales and techniques.