THC Factor
THC Factor is the apparel arm of GreenRX™ Corporation — a Wisconsin-rooted cannabis lifestyle company headquartered in Madison. We’re home to the American Cannabis Society®, founded in Madison, WI in 1978. We design and print original weed shirts, hoodies, hats, and cannabis-themed apparel under our family of brands — TYFPS®, Free Joint Friday™, Blazed Frog™, and BillyMart™. Every piece is designed in Wisconsin and shipped to fans across the United States.
Our History — A Wisconsin Cannabis Legacy Since 1978
The roots of our story run deep through Madison, Wisconsin. In 1978, the American Cannabis Society® was founded in Madison by President Bob Kundert — a pioneering voice in cannabis advocacy at a time when few were willing to speak openly about the plant. Out of that movement, the iconic Thank You For Pot Smoking® slogan was born, becoming a rallying cry for cannabis culture across the country.
For decades, ACS® and the TYFPS® brand stood as symbols of Wisconsin’s quiet but unwavering cannabis legacy. The torch has since been passed to President Jeff Kundert, Bob’s son, who continues the family’s mission of advocacy, education, and authentic cannabis lifestyle apparel.
Since 2018, the GreenRX™ brand has proudly carried that legacy forward. Started in Madison alongside the American Cannabis Society®, GreenRX™ now serves as the parent brand for a growing family of Wisconsin-born labels — including TYFPS®, Free Joint Friday™, Blazed Frog™, and BillyMart™.
Through THC Factor, we keep that legacy alive — designing original cannabis apparel that celebrates more than four decades of Wisconsin cannabis culture, advocacy, and community.
Thank you for pot smoking.