White font color to go on darker colored t-shirts - how?

This may seem odd, or really basic and I missed something, but if I want to create a word cloud that will have white font to show up on a darker colored t-shirt or mug, etc., what do I do about the background color? Choose white on white?

Thank you!

Basically you are right :) White on white will do the work.
But I suggest you doing the following:

- Choose white on black background and create your cloud
- Before printing it make black background completely transparent

Thank you!