(BORED)
With Cups being sat by office desk for some time, I've begun to notice the outer tread does not retain the same pattern consecutively.
I've always thought the 3 slits that run on the outside were identical in size but have noticed different.
There seems to be 3 variants in sizes:
1. 17mm
2. 20mm
3. 24mm
These appear to run randomly and follow no pattern in change.
Anyone picked up on this before and do you think there is some technological explanation for the variation in sizes?
