@Baldy
The 5013 print up to the top really nicely, but all my 5013s had a deep ridge 5mm from the bottom causing a faded ring around the circumference.
@webtrekker
Oh yes, Jubilee clips would do it! I reckon the inconsistency is a combination of things, but eliminating the buckle should get me closer. Some of my wraps are only half the thickness, so it's probably those ones not holding the mug's weight.