Internet of Things Business Card 0.6mm Thickness Circuit Board

This PCB is ordered on 8/20/2016 with three others PCB design. It shipped in one time to minimize the shipping cost. But i've to wait more little time than estimated delivery time. I'm very impressive about the thickness they can do, but the quality of the silkscreen is not quite good for this PCB, as you can see there is some "dust" in white color. -------------------------------------------------------------------------- How about making a business card with PCB that you can assembled, programmed, and interact with some one else? Here is some of my electronic business card sample. Actually this is a minimum system of ESP8266 schematic. I put some FTDI connector, so i can programmed easily. You can do anythings with this ESP. For me, i just create some web server so peoples can access it with their PC or smartphones. Need spent more time for development, especially for improve power or making the ESP in sleep mode. https://youtu.be/bmVFEiUUsNI