Paper's uniform mass per area makes it useful calibrating very tiny scales. 1mm² of 80 gsm paper will weigh about 80 micrograms. "Measure the mass of an eyelas

Paper's uniform mass per area makes it useful calibrating very tiny scales. 1mm² of 80 gsm paper will weigh about 80 micrograms. "Measure the mass of an eyelash with a DIY microbalance" by Applied Science https://youtu.be/ta7nlkI5K5g https://youtu.be/ta7nlkI5K5g