Even though the grout job seems unimportant compared to the glass-work, it in reality is actually - if not as important - more. It can be the final touch that really brings the piece together or ruins the piece.
In my "Will I Find Piece", the entire piece was grouted with a muted lilac grout but the glass of the center image was relatively lighter than the outer parts. It actually completely washed out the image, making the image unreadable. So I mixed some acrylic paints, made it into a wash, then carefully applied and allowed it to set.
I often come up with a conceptual grout color but I can't recall ever following through with that same color, sometimes I go lighter or darker but most of the time it's an entirely different different color. So I suggest waiting till the very end to decide a grout color.
When it comes to dying the grout, you can purchase commercial grout dyes, but I find they can be pricey. And colors are limited. I start with a neutral gray or white grout either premixed or powder form.I prefer powder, so that i can control the viscosity. Having complete control of everything in the art form is crucial. White is the best for beginners, but whenever using white in general it's a battle with white's intensity. I love using acrylic based paints, stay away from oil colors because oil will effect the composition of the grout and it will not dry properly.
The best paint out there is GOLDEN, it's pricey depending on the series. But this is because their pigments are pure and rich. Compared to Liquitex which is high in binder and has a considerably low pigment. Golden paints are beautiful and are unlike any other brands. You don't need much considering that most of the time your grout color should be semi muted so that it pulls the piece together rather than overwhelm the viewer or make the image less important.
Try not to add too much paint, because you already have enough moisture from the water added to the grout powder to make your grout mixture. The more paint the more moister and it may cause the viscosity to go down. So one tip is to make your grout a tinge dryer so that your paint if need be, will compensate with it's own moisture.
Grouting can be the most fun, because it's a hell of a lot easier, requires less patience, and allows you to get creative. In future posts, I'll talk about mediums that you can use to give even more texture and unique color effects.