» What they are: Waterproof skin appliqués that a parent can stick on a child and then personalize with a marker included with each kit. Putting a phone number on the tat makes it easier to reunite a lost child with his or her parents.

» How they work: First use an alcohol wipe to clean the skin where you want the tat (for warm-weather use, the outside of an arm, between the elbow and shoulder, is recommended; in cold weather when a child might be wearing long sleeves, the inside of the wrist works well). Make sure to avoid all lotions, sunscreen and bug sprays, which can limit the effectiveness of the adhesive. Peel the tattoo from the large backing, place on the child’s arm and press firmly for 20 seconds. Then peel off the top layer and inscribe the emergency phone number.

» The good: They do last. I applied one on a Saturday morning, and seven days and six showers later, it was still firmly attached and the message showed no signs of fading. The SafetyTats can last two weeks, according to the manufacturer.

» The bad: If there is a drawback, it’s that the tats adhere too well. Removal involves slowly peeling the sticker from the skin. Small children might fuss, as is their wont.

» Cost: The SafetyTats come in various designs in packs of six to 18 ($9.99-$19.99). Order online or from a retailer listed at safetytat.com/_cms.

–William Hageman / Chicago Tribune