I ran into an issue with teespring, where the first shirt they shipped me was much darker than they display on their website. I had ordered a Navy blue shirt and so the black font was nearly invisible.
I hope that no one else here ran into this problem, but just in case - teespring gave me a choice of new colors and shipped out a new batch free of charge!
So if you have any issue with the font (white/black) not being visible due to your selected shirt color, if you take a picture and contact teespring they should ship you another one with a different color.
I hope you guys got the shirts and that they turned out well and that you love them as much as me!