Heat-seal sole
Reference: Tredair sole
These are slabs of PVC with a slight indentation of about 2mm to keep a mid-sole in place. Otherwise the upper surface is smooth.
Cobblers weld or glue these to existing welts which are sewn to the side of the shoe, then cut or grind the edge to shape.
An existing mid-sole can be re-used to slip between this sole and the board that goes under the foot.
More info
Over time we hope to have better pictures of these caramel-coloured soles and size options. Meanwhile, just let us know the shoe size you want and we will send something a litle larger.
Slabs of PVC pastic like these are hard for cobblers to find or use. Usually the question you see on a forum is "where can I get DM soles replaced?" and the answer is something like Timpsons, a UK-national shoe repair firm that's good to quote as an answer because they can tell you if there is a branch near you that does heat=seal welding of soles onto welts.
The soles are made in lengths two thrids of an inch, or sizes, apart. There are no labels on the soles but their cartons call them 5-6. 7-8. 9-10, 11-12. Factories use them over-size and cut down, so a size 10 boot would use a size 11-12 sole. A lot of the PVC is cut-off or ground-off to get the right shape.