We call it Linenfold because the effect i want is similar to the folds of fabric hanging from a curtain pole. It is also an allusion back to Tudor period oak paneling when there was a fashion for carved “linen Fold” panels. This shows the doors behind shaped. See if you can how Si and Daren have routed out the under cuts before assembly then filled the shaped groove with cork to provide a “backup” for the cutter. The assembly is then put over the saw and cut back to the line. final shaping is then labourious handwork, moulding planes, scrapers,and finally abrasive paper.