Every time I trial a new supplier I check to see if they have any mug packaging.
I was looking for some tankards and saw some I liked on Subli Blanks. They also had some smash-proof boxes at £23 per 100. I bought 100. They are the best I've found. Super strong and white outer. Since they I've bought 2 pallets and they have been very consistent in quality. Free shipping on orders over £100 too!
We have not had a single damaged mug since switching to this packaging and so cheap.
They have lots of other goodies too. I especially like their stainless steel water bottles.
http://www.subliblanks.com/Consumabl...Shipping-Boxes