Who doesn’t remember that classic two-color eraser we all had in our pencil cases? The pink side was for pencil marks—but the blue side? Most of us thought it was meant to erase ink. But let’s be honest: it never really worked. Instead, it often tore the paper and left us annoyed.

So, what is the blue side actually for? Turns out, it has some pretty clever uses you might not know about—especially if you’re into DIY or crafts.

The Big Myth: It Erases Ink

For years, people believed the blue part could remove pen marks. But in reality, it doesn’t do that well at all. It’s like trying to clean a wine spill with soda water—well-intentioned but disappointing. That blue side was actually made for other things—and they’re pretty useful if you know when to use them.

Use It on Wood

If you’ve ever put together a wooden piece of furniture and marked it up with pencil lines, this is where the blue eraser shines. It’s got a rough texture, thanks to pumice inside, which acts like a super fine sandpaper. It gently rubs away pencil marks on wood without scratching or ruining the surface.

Works on Concrete Walls Too

Professionals in construction often mark up walls to measure or plan. The blue eraser is great for cleaning those pencil marks off concrete or plaster once the job’s done. It’s much more effective than a regular eraser on rough surfaces like these.