So I marked out where the shirt would fall on my wife's stomach. I printed the battery cover, first few layers in black then manually switched the colors to blue. Once it was done I hot glued it to the shirt. Once the hot glue had hardened i turned the shirt inside out and hot glued the board and LEDs to the shirt. To soften the shape of the electronics board and not make the shirt painful when wearing I used this flexible foam material I had left over from when some furniture was delivered (i'll be honest not sure what it is but it's pretty strong and easy to use). I put that on both sides of the board and the back side of the LED strip. Once everything was all glued up I attached the battery pack to test it out.

I am very happy with the final result!!!