I have a set of cups -- didn't pay much -- and they look like they could be either Miller,Bertram, or Phoenix.  I'll guess Phoenix because  I would think the others are highly valued.  But as I look at photos I ask, how can you reliably tell the difference? Any advice?

PS I don't use them as they don't stack well or do some moves (the Fako) that I like to do....

They're rather easy to tell apart from each other. Bill Palmer's website should help a lot in indentifying them.

Millers usually have a "line" between the lip and the bead, caused by the type of roller used. You can even see it in the picture at the top of this forum. Bertrams don't have this line. Phoenix cups are less accurately made than the other two, don't stack as well, and usually have an open bead around the mouth of the cup, much more pronounced than the Millers.

Can you post a photo for us?