I've been seeing a lot of threads about people wondering about manufacturing issues with pins, especially when it comes to pins with see-through/stained glass elements. I've designed and worked with manufactures for lapel pins in the past (not Disney), so I know a lot about the process, but thought some of you would like to know!
The easiest way to explain the process is with this video from How It's Made!
[video=youtube;k_EH_eHnHzY]http://www.youtube.com/watch?v=k_EH_eHnHzY[/video]
Something I'd like you to see is how the coloring is done. This starts at about the 4:15 mark.
People have been wondering about the backs of pins being flat with stained glass/see-through areas.
This is because the enamel they use is liquid! To accurately fill the see-through area, the pin has to be flat against something so the color doesn't spill out behind the pin. If the Mickey waffle pattern was around these areas the pin would not be flat against a surface and the color would fill into whatever Mickey shapes are closest to the opening.
It's a little similar to the Sun Catcher melted crystal craft kits. In those you'd fill an area with little colored crystals, pop it in the oven, and they'd melt into the framework of whatever the sun catcher is.
You can see that in action here (sorry, can only embed 1 video)
Only difference with professional pins is the color is a liquid and instead of popping it into an oven, it just has to dry on a flat surface.