As a DIY'er what I know from experience is that as the grout line gets smaller, it's more difficult to lay the tile - especially if the tile is not perfectly square. I'd say a 1/16" grout line requires a good tile setter.

This tile is rectified, so as long as you don't go bigger than 12x12, you can use a 1/16" grout joint. Also, being that you've chosen Laticrete's Silver Shadow, if you go with the Permacolor series, it's a portland cement based grout that uses a much finer sand than conventional portland cement grouts, and therefore can be used in any size grout joint, thin, or standard.

Weedyacres, I agree that a good tile installer does a dry layout first to assess the best way to install the tiles to create as little cuts as possible. If the tile installer would have started the diamond design at my door next to the rug area and worked his way forward so that at least the door area had tiles right up against it and most of the rug area did also, the window area would have no gaps and there would only be a 2" gap by the wall opposite the door. That gap would have been covered up by a 1 7/8th diamond cut of the tile in a few areas leaving the 1/8th width between the other tiles. The tile would have not fell out after being glued and having a quarter round on top. The installer started in the middle of the floor and then told me if he did not due the border I would waste so many tiles since he would have to put tiny pieces about 1/4th to 3/4th all along the edges. After he was done, I only saw spaces of 1 3/8th to 1 1/2 spaces at the door so he was wrong. He also forgot about the other wall on the other side of the door not having to have the tiles 1/8th from the wall since a quarter round would be covering the area. He tried so hard and I know I could have never cut those tiles so I feel very bad but in person, the problems were more noticeable. I also did not want a border in such a little area and I had shown him a picture of what I wanted and he told me 1/8th width was no problem for him with the spacers. I wish when the installer asked me where we should start the tiles, I wish I would have told him, let's lay them all out first and then we shall see how they fit and then I would have realized the tiles should start at the door. I was busy with ear plugs on trying to work but I could not work once he started the border since it was upsetting me. If I had a bigger foyer area, the border would have been nice if it was straight. Once the quarter rounds would have been put back on the sides of the wall, the tiles would have not looked centered anyway and the 3" wide X 12" boards would have not been the same size any more as on the other two walls without the quarter rounds. I now have no tiles and only cement floors blocked by gates but I could not let him do the middle foyer that had 4 doors since I do not feel he knew how to handle doors. Here is a link that might be useful: Album with some pics of the uneven grout lines mainly due to putting a border in that I did not want that created more cuts of the tile making it busier

Well, we have something in common: Interest in Quantum Physics, a fascinating subject. I want to check out her work.