Think about your favorite T-shirt. You know, the one that gets softer after each wash, the one with the memories. JP and Sarah Box think kids deserve the same special relationship with their wardrobe as every grown-up Coloradan. For these Denver parents of three-year-old twins, that meant creating pint-sized options in 100 percent Merino wool for their now one-year-old clothing company, Chasing Windmills.

First came their love for the fabric, then came the twins. When the couple hunted for mini Merino wool apparel, they weren’t impressed with the options. “As parents, we became more simple minded,” Sarah says. “We want to live deliberately. We consciously started deciding what we wanted in our lives. Kids make you think like that.” So during an exhausted, middle-of-the-night feeding in their Bonnie Brae home, the new parents decided to start a business.

Merino Wool-made kids products just made sense: Besides being super soft, the fabric lends itself to little ones as it’s naturally anti-microbial (it doesn’t harbor spit-up smells), temperature regulating, and stretches just enough for the perfect burrito baby swaddle. The pair sourced wool from “happy sheep” from the same New Zealand farm that supplies other big outdoor brands like Smartwool.

The first Chasing Windmills line focused on the nursery, with soft baby rompers, swaddling blankets, and crib sheets that we wish came in king size. Now their kids (and in-house product testers) have bypassed their newborn days and are onto adventure hikes and neighborhood exploring, which inspired last month’s release of quick-dry toddler T-shirts ($38), shorts ($35), and hoodies ($50). “Our love of Merino comes from our love for the outdoors,” says JP, a former lawyer. “The new toddler gear actually puts kids outside.”

The new wares also come with an opportunity to teach kids a bit about the green material. Once kids wear out a shirt, it can be buried in the dirt and disappears back into the Earth in about six months. And there’s no worry about running out of Merino wool—it’s a naturally renewable fiber, as long as the happy sheep keep grazing and growing new coats—which is good because a new line of little long underwear is set to be released this fall, just in time for cool-weather camping.