He would use tracing paper to allow him to create multiple images from the same drawing.

会用描同一幅画绘制成多个像。

Tracing paper, toilet roll is a liberty.

描、厕，这直是放肆。

You know it's your flatmate's turn to buy the toilet roll when they get the cheapest, nastiest, budget toilet roll that could be used as tracing paper.

你知道该轮到室友买厕的时，会买最便宜、最粗糙、像预算一样的厕，那东西直可以当描用了。

You know it's your flatmate's turn to buy the toilet roll when they get the cheapest, nastiest, budget toilet roll that can be used as tracing paper.

你知道该轮到你的室友买厕了，因为会买最便宜、最粗糙、像预算一样的厕，那玩意儿都能当描用了。