A random fact about:
The Blue Bit of the Rubber
You’re probably like 95% of the population believing that the red bit is for pencil and the blue bit is for pen. We have all tried in vain to rub out biro with the blue end, and ended up just destroying the paper.
The blue end is actually designed for erasing pencil marks on heavy grades of paper or really dark marks. Use the red end for light paper and precision erasing, and the blue end for coarse and grainy paper such as artists’ sketch pads.
Shop for erasers.