The application of grout fills the gaps and interstices between the tesserae, completing the mosaic. The grout will unify the tesserae into a cohesive design.

Grouting can be the scariest and the most rewarding part of a project. As you stare at hours of work, a million things spin through your mind. What color? What kind of Grout? Where do I start? What if.......? You know that grout can make or break your mosaic artwork. The following sections contain tips and guidelines that will hopefully relieve some of your anxiety. Grout is optional; there are many materials that do not invite the grouting process, including stone, shells, pebbles, Italian smalti, and found objects.

Most grouts are a cement-based mixture. The basic ingredients are Portland cement, sand, and water; a chemical hardening process begins once they are mixed. It's a chemical process that cures. The grout landscape is ever-changing and is driven by the commercial tile trade. Best advice for anyone, beginner to professional: Read the manufacturer's specifications. These can be found on the back of the bag or the manufacturer's website.

Grout has little adhesive properties and cannot be used to "stick" tiles in place.

Grout comes in sanded, unsanded, premixed, and epoxy versions. To learn more, visit(Types of Grout). We recommend using polymer fortified sanded grout for most mosaics. Non-sanded grout may crack over time if grout lines exceed 1/8”.

There are many brands of grout commercially available. As mentioned earlier, ALWAYS choose a Polymer-fortified brand. If this type is unavailable, you can use standard grout (no admix), and liquid admixtures. These products are typically sold side by side. Check the manufacturer's recommendations on the back of the package.