3 Grout pens.

The Grout Pen White Tile Paint Marker is a waterproof and matte grout colorant and sealer pen manufactured by Rainbow Chalk Markers Limited in the United Kingdom. It is designed for use on floor tiles in modern style bathrooms, kitchens, and patios. The pen has a 5mm tip width and is made of grout paint. Its features include waterproofing and a matte finish.