Young people on social media are showing off their 12-year-old water bottles, sweaters from high school with patched holes and dish rags made from cut up old T-shirts.

It’s all part of a trend that has taken social media by storm in recent months called “underconsumption core,” where users boast about how they’re continuing to make use of the things they already own and repurpose household items instead of buying new ones, all while saving money along the way.