The Circular Economy is viewed as an important driver for resolving resource issues and tackling sustainability issues more broadly. The fashion industry operates in a largely linear way and suffers from various environmental, societal and economic challenges. In a Circular Economy, first and foremost, products need to be retained at the highest level, thus slowing resource loops. Slowing resource loops goes against current fast fashion trends and therefore appears the most difficult approach to pursue. This paper investigates how a large established retailer aims to slow resource loops as part of a broader project targeted to significantly reduce textile waste to landfill. The retailer collaborated with a university partner to pursue circular business model experiments. This paper reports on the approach for a slowing resource loops experiment around building sewing capabilities. Suggestions for future research and practice on circular business model experimentation are included.