noun
fins (of a fountain pen feed); comb feed
Technical term in fountain pen design; refers to the comb-like grooves on the feed that regulate ink flow.
万年筆の櫛溝が詰まると、インクの出が悪くなる。
When the fins of a fountain pen feed get clogged, ink flow becomes poor.
このペン先は櫛溝の数が多いので、インクが安定して供給される。
This nib has many fins on the feed, so ink is supplied steadily.