What brand of transparent plastic ruler (15cm) will not fall off the scale? The ruler I buy is always out of scale. I always keep buying it, which is a waste.

Generally, the short scale of 15 cm is printed, and it's only a matter of time. In fact, buy a longer acrylic material (about 40 cm in length). These are basically used for drawing, and the scales are really engraved. If you are not sure, you can go to the scene or ask customer service. Then buy it back and cut it short. 20cm is enough for school. If you don't throw it away, put it with the eraser and you can use it after graduation. Don't worry about losing the scale.