The grout in our bathroom was not dirty — it was stained. I scrubbed it with bleach. I scrubbed it with baking soda paste. I used a steam cleaner. Nothing worked because the grout itself had discolored. The color was baked in.

Re-grouting the whole bathroom was going to take a full weekend and cost a couple hundred dollars in tools and materials. I was about to commit to it when a neighbor mentioned grout pens.

I was skeptical. A pen? For grout? But it cost eight dollars and took forty minutes. The bathroom looked new. That was two years ago and the color is still holding.

What a Grout Pen Actually Does

A grout pen is essentially paint for grout lines. It contains pigmented sealant that bonds to the porous grout surface. It covers stains, evens out color, and adds a protective layer that resists future staining.

It is not a permanent fix like re-grouting. But for cosmetic improvement that lasts a year or two, it is hard to beat.

How to Do It Right

1. Clean the grout first. The pen covers stains but it will not stick to dirt or soap scum. Scrub with a grout brush and let it dry completely.
2. Shake the pen well. The pigment settles. Shake for a full minute.
3. Press the tip down to start the flow. It takes a few pumps. Test on a paper towel first.
4. Draw along the grout line. Go slow. The tip is designed to fit into the groove. Overlap lines slightly.
5. Wipe excess off the tile immediately. A damp cloth works. Once it dries on the tile surface it is harder to remove.

One pen covers about 150 linear feet of standard grout lines. Measure your bathroom first — you might need two.

Color Matching

Most grout pens come in white, bright white, and a few shades of gray and beige. If your grout is a custom color, match as close as you can. Slightly lighter looks better than slightly darker — dark grout on light tile stands out in a bad way.

I used bright white on white tile with old, yellowed grout. The difference was dramatic. It went from “needs renovation” to “looks clean” in under an hour.

Will It Last?

In a shower that gets daily use, expect to redo it every 12-18 months. On a bathroom floor with less water exposure, it can last two to three years. It holds up to regular mopping and cleaning.

I redid mine after about 18 months. The second application took twenty minutes because I knew what I was doing.