Hej Kate

Jeg tror, der menes, at de kramper, der anvendes, er dækkede/isolerede med skumgummi (eller andet skummateriale, der anvendes). De fleste Google-hits handlede om møbelfabrikation, der forklarede om "foam-over", f.eks.:

The armrest is the most difficult part... Start at one corner of the table and lay the near edge of the fake leather upside-down just an inch from the edge of the table. Staple it down. Lay the foam over these staples and wrap the material up around the foam and stretch it all the way down to the bottom piece of plywood. Staple it to the bottom of the table. See the following diagram to see how this is done and the following picture to see how the result should look.

(www.pjhealy.com/blackjack/table/)

Håber, det hjælper dig videre.
Hilsen
Helle