This is a remix of the Dummy 13 chest armor by @soozafone, that makes the numbers on the chest more visible.
Make sure to print lower and upper chest in contrasting colors and to use supports on the lower chest. I provided a #10 chest piece as an example, but feel free to put whatever number/logo you want through the solid piece.
The author remixed this model.
I thinned out the front of the upper chest armor, and increases the height of the lower chest behind it. This allows you to punch numbers through the upper chest showing the underlying lower chest piece.
Note: The lower chest piece here does require supports to print properly.