3 Way or Triple Heart Tanning stickers as they are called are a great way to measure your tan. It is always hard to see your tanning progress by looking in the mirror. Tanning is a gradual process and therefore your color changes throughout the day and from one day to the next. The only effective way to measure your tanning progress is to use a tanning sticker in the same spot each time you tan. Almost everyone is surprised by how tan they are once they have used a heart or combination of heart designs for a few weeks. Show The Love!