ABSTRACT Transparent wood and translucent wood are attracting attention as promising sustainable optical materials. Typically, translucent wood is prepared through chemical treatments (bleaching, etc.); thus, there is a need for more ecofriendly, sustainable preparation methods. In this study, translucent wood was prepared by precisely controlling the compression conditions. Natural wood was densified to reduce internal voids that cause light scattering, resulting in a light transmittance of more than 60% for visible light (@600 nm, sample thickness: ∼0.3 mm). This method was particularly effective for softwood and can be applied to hardwood, accelerating the development of ecofriendly optical materials.