If you look at return reasons across an indoor footwear range, they collapse into two clusters. Neither is a design problem.

Fault one: the size runs small

Slippers are worn with or without socks, on feet that swell during the day, and often bought one size up by habit. A last that matches a shoe last will produce complaints. Most returns are avoided by cutting half a size up and saying so clearly on the listing.

Fault two: the sole lifts after washing

House slippers get washed more than any other footwear. If the bonding process is not tested against repeated washing, the sole separates and the product comes back.

What to ask before you order

• What last is this cut on, and how does it compare to a standard shoe size?
• Has the sole bond been wash-tested, and can I see the report?
• What is the return rate on this construction from other buyers?