Bemused by strange hue on a Mug

[Lucifax]

Just had the same problem, 72 mugs sent to a regular client and 35 of them have bled. I can only assume that I packed them back into the boxes whilst they were too warm. Granted I was cracking through them with a number of presses on the go, and hence may not have left them infront of the fan for long enough. Due to the large number of orders that day it was a very late night as well. Mistakes like that really annoy me, as it's my fault and avoidable.

Onwards.

Janners

Xmas hazard I guess, do you think the coating makes a difference? Never seen it before and only recently started using Listawood mugs.