@zens@merveilles.town the question of "is it UV or is it oxygen" is an interesting one as people in retro communities swear up and down UV exposure is what yellows plastics and i've had a dreamcast yellow to smoker teeth tinge completely light-sealed in a closet

UV affects thermal paper and keeping it dark should in theory keep it longer, but you're still fighting against the chemical stability of the paper itself regardless

i'm not sure, for thermal paper, if oxygen plays a part