A note on the inks, because transparency is everything :)
I have stamped these on many many shirts! Seriously don’t check the inside of my shirts ;) I have also wash tested these.
For both inks, as with any fabric stamp, it’s best to leave the the fabric overnight after stamping before washing to ensure it’s set.
The black ink stays vibrant and dark after washing and will last a long time.
The white ink stays on after washing, but does become a little more dull. It gets the job done but may not last as long. This is just due to the nature of white ink pigment.