I was very nervous about using these given the mixed reviews, so hopefully this helps anyone on the fence about using them. I bought two different colors, the gray and the white. The gray definitely has a slight blue-ish cast, so if that is going to bother you use a different brand. The white is a true bright white without any ivory or yellow. Do not count on this matching your existing grout. You will not be able to just touch up a few areas. Just plan on doing the entire room. As to usage, I was pleasantly surprised by how far these went. I did the entire floor of my large master bathroom plus a little of the shower with one pen. The shower floor has small hex tile with larger grout lines so that took a little over two pens. Some tips: shake very well when first taking out of the package and any time you start working again after a pause. Depress the tip several times on to a paper plate or directly onto the grout line to get the paint flowing. Press very lightly when going over the grout. The tips lasted almost all the way to the end of my project. If the coverage starts to thin, pause and depress the tip a few more times. I would do about a 1x1 foot area, then pass over it lightly with a damp paper towel to get any overage off the tile. It is pretty forgiving and you have quite a bit of working time before it dries completely on the tile. If the tip gets too ragged you can pull it out (I used the damp paper towel) and flip it around. This was not a quick task but it went faster than I thought it would. I was worried the white would look too bright, but it just makes everything look so much cleaner. Very happy with this product!

very very bright white, if your tiles aren’t super bright white it might look a little off, but honestly a great quick fix. it isn’t as precise as i’d like, especially if your grout lines aren’t perfect or vary in depth/thickness, but overall easy to use and worked as described

Works but not much in the pen. Would need many to cover a large area.

I did my bathroom floor with gray grout and it came out perfect. It gave my bathroom a whole new look and everyone loved it. I am doing the grout on my tile on the kitchen wall. It looks great.

This is a repeat order. Love this product. When your grout is dirty and nothing seems to help, this will work wonders. Easy to apply, long lasting.

This product is easy to use and makes the grout look great, but the tip easily deteriorates, though Im not sure to what extent this is a problem with its actual application.

I wore the nub out before it was empty but I may have just been using it wrong. Impressed. Did a way better job than I expected. Recommend if you diy

easy to use but the end brush flatten out quickly

I like the way the pens work initially but the points wear down and fray very fast. Then you can’t get them into the grout space between the tile

The marker tip did not last more than 1/3 capacity of marker. I have to cut open the marker top and use a point paint bush to use up the paint left inside the marker. For an average shower tile wall, you need at least 2-3 markers.