Dimensions of starbrite tattoo ink bottles?

This is an odd question I'm sure, but a friend of mine does tattoos, and his birthday is coming up. I am wanting to make him a nice decorative rack for his inks since I am fairly gifted with woodworking, but I have no clue what dimensions the bottles are. I do know that he buys starbrite inks exclusively, in 4 ounce bottles. Is there anyone out here that can tell me what the dimensions of these bottles are (with caps and all) so that I can make the rack so it perfectly fits the bottles. I also believe there are 46 colors, but if anyone can verify this, that would be great to so I can get this made for him. Thanks in advance