The worker rolled the paint onto the wall with a roller.
Tips
usage
Common compounds: 滚筒洗衣机 (front-loading drum washer, as opposed to 波轮洗衣机 top-loading), 滚筒打印机 (cylinder printer), 滚筒刷 (paint roller). Whenever a rotating cylindrical part is involved - washers, printers, conveyor systems - 滚筒 is the right word.
memory
滚 (to roll) + 筒 (tube/cylinder) - 'rolling cylinder'. 筒 is the same character as in 笔筒 (pen holder) and 话筒 (microphone, lit. 'speech tube').
