Why I Don't Grout My Mosaics

If you work in mosaic, you probably notice pretty quickly that mine are not grouted. I leave grout out because of what I want the image to do, not because I think the rest of you should stop using it.

To me, grout is another visual material in the image, not neutral filler. Change the width, value or color between tesserae and you change how those tesserae separate, join and compete with one another, which can help one mosaic and hurt another.

I work with stained glass and place the pieces tightly, so many of the intervals diminish when I step back. They never truly disappear, though, and a narrow dark interval can strengthen an edge while a wider one can cut an unwanted line through a face or separate pieces I wanted the eye to combine.

The support changes the answer too. Clear and translucent glass can behave very differently over light and dark surfaces, so reflections, values and local emphasis can shift even when I have not changed a single piece of glass.

So when another mosaicist asks, "Should this be grouted?" I want to turn the question around. I would rather ask what the grout will do to this particular image, because one question asks for a rule and the other asks for a consequence we can actually look for.

I feel the same way about grinding glass, conventional andamento or any technique we inherit as normal practice. If a method gives the image a consequence we want, that is a reason to use it; if it does not, tradition by itself does not settle the question.