Original Pin HERE.
From The Mother:
Okay, these things are just cool. Since the original pin was a little short on instructions (I can't blame her, it's a pin from an Etsy shop), we had to try and figure it out ourselves. We had some old shirts laying around, so there was no worry if we ruined them, and found our stencils online by searching for silhouette images.
All of the kids quickly chose their pictures, and then we had to change their minds - I'm not doing a four stage rainbow with sparkles, thankyou - and settled on a lion, a castle, a butterfly and a princess crown. We guessed on the bleach spray, we used a 3 to 1 ratio, bleach to water and it acted fairly quickly...with the exception of the princess crown which we had to spray and then put in the sun to get it to change color.