V1 = UNIFORM APPEARANCE
Differences among pieces from the same production run are minimal.
V2 = SLIGHT VARIATION
Clearly distinguishable differences in texture and/or pattern with similar colors.
V3 = MODERATE VARIATION
While the colors present on a single piece of tile will be indicative of the colors to be expected on the other tiles, the amount of colors on each piece will vary significantly.
V4 = SUBSTANTIAL VARIATION
Random color differences from tile to tile, so that one tile may have totally different colors from that on other tiles. Thus, the final installation will be unique.