To help more with form the cups were tested for how well they retained heat. Each cup had boiling water poured in to it and timed to see how long it took for the temperature to fall below 69C.
The first cups tested have the smallest openings and times for the looked like this
Thickest 4:00 min
Medium 3:43 min (averages)
Thinest 3:32 min
The second cups to be tested were the ones with the second biggest openings on top and there times are as followed
Thickest 2:52 min
Medium 2:50 min (averages)
Thinest 2:45 min
Thickest 2:00 min
Medium 1:58 min (averages)
Thinest 1:55 min
For ease with drinking and heat retention I will be using the second form for my final prototype.
One thing high lighted from this testing was that the cups with out handles were unbearable to hold from the heat. This will need to be sorted as I prefer cups without handles. Shown below is a cup with a handle and another without.
Without does look better.