See my other thread. I thought I'd add here, as well, that there is a simple solution to the problem of the 3" adapters. This works, and in IMHO is easier than using pliers, broomsticks, or taking pieces off the standard adapters.
In the case of those rolls with smaller diameter cores, order the following 3" adapter for a different spindle and printer --
C6090-60112
This adapter fits on the "fixed" end of the Z3100 spindle just fine. It has to be pushed on the removal part of the spindle and requires a little force. It is not a perfect fit -- but you can get it on OK.
This adapter is just *slightly* smaller. It fits less tightly inside the cores.
For those cores that are smaller in diameter, like the Hahnemuhle Photo Rag, the C6090-60112 is perfect. The very slight difference in size makes all the difference when you push it on and pull it off.
For other cores (I believe Ink Jet Arts Ceramic is an example) the C6090-60112 would be too lose, and you want to use the standard adapter.
When you order these, do it on-line -- not by calling them -- as I explained in my other thread.