Why grout some pieces and not others? My preference is for ungrouted mosaics in the main. The reason being is that in this way you can sustain the depth of color. When you grout a piece of art work, the grout you choose is as important if not more important than the color of your mosaic itself. The reason for this is that depending on your choice of grout, the grout can pull the image together or leave it feeling fragmented. It is important to experiment with different grout colors prior to completing your art work. It is a tragic experience to have spent weeks working on a piece only to discover after you have grouted, that you made the wrong color choice. So you may be wondering how you experiment without getting dirty? The answer is simple – draw the image first, photocopy several times and then fill in the grout spaces with various grout colors before deciding upon your final choice. Here’s an example of a decision making process. I have used a simple design by Mary Newell DePalma to illustrate my point.
In the first drawing I have colored the spaces between the mosaic pieces black- to represent the effect black grout would have on the piece. It produces a vibrant striking result and the central image pops.
In the image below, I have gone for a mid grey grout. This is a very common choice. You can see that the effect is to tone the piece down, while creating a coherent effect, bringing the image together. The central image no longer pops.
In the final example I have left the spaces blank- representing the effect white grout would have on the piece. It is clear to see that each piece becomes highlighted and the overall effect is somewhat fragmented and the background holds the same depth of effect as the central image. White grout is a good choice for light or pale color schemes, particularly pique assiette. The darker your mosaic, the use of a white grout will produce a very fragmented effect – fine if that’s your aim – but devastating if its not.
Many a mosaic I have ruined choosing the wrong grout color. The rule of thumb is that the more contrasting the grout color the more visible and fragmented a piece will look. I have always found a mid to dark grey the safe option. While I like the drama of black grout – as it accentuates the colors surrounding it. If using black with other dark colors then the colors meld together. Lighter colors with black become more clearly defined.
Here is an example of black grout with black tile, it produces a solid color pleasing to the eye.
Below you can see the effect of using a black grout with light wall tiles, the effect is that each individual tile shards are individually clearly visible and can be easily seen, producing something of a fragmented effect. In this piece I would have been better to have used a mid to light grey to produce a more coherent reading.
In contrast below is a vibrant colored tile mandala with white and yellow grout. I colored the yellow grout at the center of the mandala. The white grout here also produces a fragmented effect which for this piece is effective.
On the piece below I have used a dark grey grout and you can see that the top of the piece is rather fragmented and as the grey colored grout moves down the piece the background becomes more solid and coherent. This is an excellent piece to show the effect of a grout color on the choice of tiles.
So when choosing grout color remember that the space between your mosaic pieces will make up a considerable amount of your piece, about one third of the surface area. So your grout choice will have an enormous impact on the end result.
A darker grey grout tends to be my safe choice when using wall tile as the color pulls together into a harmonious whole. Grey grout also looks a bit like cement which makes it an ideal choice for outdoor projects. Be sure to experiment.