Though this was a great value for what it comes with, the rulers are plastic and I use them mostly for bullet journaling and creating lines for different creative projects of mine. The rulers being plastic and clear are great so that I know what my end results will look like. The black lines for measurement purposes serves as a great guide too. However, I guess these were popped out of a cut out or mold because there are plastic points on some edges where it should be flat and it gives me a bump whenever I go over that area on some of the rulers.