Barefoot Tess was by far the most frequently mentioned shop by far on the original blog post which sparked this forum.
This US website ships worldwide stocks an extensive variety of styles in size 11-15 US (that’s up to size 13 UK).
The shoe prices are very reasonable, but international shipping is expensive, and you may be liable for customs charges for large orders.
The only caveat is that some report that most styles are more suited to those with average or narrow width feet. However some styles are particularly suitable for those with wide feet e.g. Blowfish styles, Canadian muks boots and colourful wellies.
They often run special offers and discount coupons on the site, so it’s worth checking the website or the sales forum here to keep up to date.
