I did a fair amount of research prior to buying my first set of clay chips.
Pics located at
http://bnimblemo.tripod.com/chips/
One thing I learned very early, if you want near perfect tolerances and high resolution graphics, go with injection molded chips. If you want classic casino sound, feel and quality, go with compression molded.
I ended up going with buypokerchips.com "Modern Clays". You can see from a couple of the pics a slight difference in thickness. This is only slightly noticeable with stacks of 25. None of my poker buddies have ever noticed the difference. I'm just a perfectionist type that will notice these things. However, I have come to accept the minor inconsistencies. These are awesome chips and I am very excited to get the Pharaoh's in my hands!
Below is an interesting quote from
www.nevadajacks.net
NOTE: Making clay chips is a slow and labor intensive process. Unlike inexpensive composite chips, each clay chip may vary slightly from the next. While weight and size are consistent; the appearance of colors, edge spots and inlay placement may vary slightly. These chips are made to the highest casino specifications. Some buyers perceive this as a defect. This is just the characteristics of clay chips. If you are a perfectionist... purchase 7 cent Chinese imports. If you want Casino Quality... this is IT. There are NO exchanges for the above reasons. If returned, customer is responsible for all shipping and restocking fees.