The mosaic mirror I repaired for my friend (see this post) is finished. After gluing in the replacement tiles, I decided to grout the whole thing. It wasn’t originally grouted - the tiles were obviously supposed to fit in tight so there would be no need. However, the were several scattered section of maybe 3” x 5” where they didn’t fit tight, and bits of white mastic showed through.
So I mixed up some snow white grout with blue and green powdered pigments to get a pretty good match.
Dummy that I am, I forgot that it was going to dry considerably lighter, so those gaps were still quite noticeable.
After I cleaned it up, I went over the whole thing with a thin wash of acrylic paint – green black, titanium white and a touch of french ultramarine blue. The lines disappeared and here’s the finished piece: