Modified wood and transparent wood composites, and systems and methods for forming and use thereof

A method comprising:

• subjecting a contiguous block of wood to a chemical treatment for a first time so as to remove lignin from first and second sections within the contiguous block while substantially retaining a cellulose-based microstructure of the wood in its natural state, the first-second section being adjacent to the second first section, the first time being selected such that at least 90% of the lignin of the wood in the first section is removed while no more than 75% of the lignin in the second section is removed;
• and
• infiltrating the contiguous block with a polymer so as to fill open spaces within the retained cellulose-based microstructure of the first and second sections, the polymer having a refractive index substantially matching a refractive index of cellulose, wherein, after the infiltrating, the first section is substantially transparent to light having a wavelength of 600 nm, and the second section is translucent to the light having a wavelength of 600 nm.